diff --git a/shell/platform/darwin/ios/BUILD.gn b/shell/platform/darwin/ios/BUILD.gn
index 37f6b3fe65eb0..02ea92bc9d500 100644
--- a/shell/platform/darwin/ios/BUILD.gn
+++ b/shell/platform/darwin/ios/BUILD.gn
@@ -105,6 +105,8 @@ source_set("flutter_framework_source_arc") {
     "framework/Source/FlutterUndoManagerPlugin.mm",
     "framework/Source/FlutterView.h",
     "framework/Source/FlutterView.mm",
+    "framework/Source/FlutterViewController.mm",
+    "framework/Source/FlutterViewController_Internal.h",
     "framework/Source/FlutterViewResponder.h",
     "framework/Source/KeyCodeMap.g.mm",
     "framework/Source/KeyCodeMap_Internal.h",
@@ -175,6 +177,7 @@ source_set("flutter_framework_source_arc") {
     "//flutter/shell/platform/darwin/graphics",
     "//flutter/shell/platform/embedder:embedder_as_internal_library",
     "//flutter/shell/profiling:profiling",
+    "//flutter/third_party/spring_animation",
   ]
 }
 
@@ -189,8 +192,6 @@ source_set("flutter_framework_source") {
     # iOS embedder is migrating to ARC.
     # New files are highly encouraged to be in ARC.
     # To add new files in ARC, add them to the `flutter_framework_source_arc` target.
-    "framework/Source/FlutterViewController.mm",
-    "framework/Source/FlutterViewController_Internal.h",
     "platform_view_ios.h",
     "platform_view_ios.mm",
   ]
@@ -210,7 +211,6 @@ source_set("flutter_framework_source") {
     "//flutter/shell/platform/darwin/common:framework_common",
     "//flutter/shell/platform/embedder:embedder_as_internal_library",
     "//flutter/shell/profiling:profiling",
-    "//flutter/third_party/spring_animation",
   ]
 
   public_configs = [
diff --git a/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm b/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
index ebf48bdd1076a..2ef686974f793 100644
--- a/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
+++ b/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
@@ -13,7 +13,6 @@
 #include "flutter/fml/memory/weak_ptr.h"
 #include "flutter/fml/message_loop.h"
 #include "flutter/fml/platform/darwin/platform_version.h"
-#include "flutter/fml/platform/darwin/scoped_nsobject.h"
 #include "flutter/runtime/ptrace_check.h"
 #include "flutter/shell/common/thread_host.h"
 #import "flutter/shell/platform/darwin/common/framework/Source/FlutterBinaryMessengerRelay.h"
@@ -34,6 +33,8 @@
 #import "flutter/shell/platform/embedder/embedder.h"
 #import "flutter/third_party/spring_animation/spring_animation.h"
 
+FLUTTER_ASSERT_ARC
+
 static constexpr int kMicrosecondsPerSecond = 1000 * 1000;
 static constexpr CGFloat kScrollViewContentSize = 2.0;
 
@@ -64,10 +65,29 @@ @interface FlutterViewController () <FlutterBinaryMessenger, UIScrollViewDelegat
 // https://github.com/flutter/flutter/issues/138168
 @property(nonatomic, readonly) int64_t viewIdentifier;
 
+// We keep a separate reference to this and create it ahead of time because we want to be able to
+// set up a shell along with its platform view before the view has to appear.
+@property(nonatomic, strong) FlutterView* flutterView;
+@property(nonatomic, strong) void (^flutterViewRenderedCallback)(void);
+
+@property(nonatomic, assign) UIInterfaceOrientationMask orientationPreferences;
+@property(nonatomic, assign) UIStatusBarStyle statusBarStyle;
+@property(nonatomic, assign) BOOL initialized;
+@property(nonatomic, assign) BOOL engineNeedsLaunch;
+
 @property(nonatomic, readwrite, getter=isDisplayingFlutterUI) BOOL displayingFlutterUI;
 @property(nonatomic, assign) BOOL isHomeIndicatorHidden;
 @property(nonatomic, assign) BOOL isPresentingViewControllerAnimating;
 
+@property(nonatomic, strong) NSMutableSet<NSNumber*>* ongoingTouches;
+// This scroll view is a workaround to accommodate iOS 13 and higher.  There isn't a way to get
+// touches on the status bar to trigger scrolling to the top of a scroll view.  We place a
+// UIScrollView with height zero and a content offset so we can get those events. See also:
+// https://github.com/flutter/flutter/issues/35050
+@property(nonatomic, strong) UIScrollView* scrollView;
+@property(nonatomic, strong) UIView* keyboardAnimationView;
+@property(nonatomic, strong) SpringAnimation* keyboardSpringAnimation;
+
 /**
  * Whether we should ignore viewport metrics updates during rotation transition.
  */
@@ -78,80 +98,71 @@ @interface FlutterViewController () <FlutterBinaryMessenger, UIScrollViewDelegat
  */
 @property(nonatomic, assign) CGFloat targetViewInsetBottom;
 @property(nonatomic, assign) CGFloat originalViewInsetBottom;
-@property(nonatomic, retain) VSyncClient* keyboardAnimationVSyncClient;
+@property(nonatomic, strong) VSyncClient* keyboardAnimationVSyncClient;
 @property(nonatomic, assign) BOOL keyboardAnimationIsShowing;
 @property(nonatomic, assign) fml::TimePoint keyboardAnimationStartTime;
 @property(nonatomic, assign) BOOL isKeyboardInOrTransitioningFromBackground;
 
+/// Timestamp after which a scroll inertia cancel event should be inferred.
+@property(nonatomic, assign) NSTimeInterval scrollInertiaEventStartline;
+
+/// When an iOS app is running in emulation on an Apple Silicon Mac, trackpad input goes through
+/// a translation layer, and events are not received with precise deltas. Due to this, we can't
+/// rely on checking for a stationary trackpad event. Fortunately, AppKit will send an event of
+/// type UIEventTypeScroll following a scroll when inertia should stop. This field is needed to
+/// estimate if such an event represents the natural end of scrolling inertia or a user-initiated
+/// cancellation.
+@property(nonatomic, assign) NSTimeInterval scrollInertiaEventAppKitDeadline;
+
 /// VSyncClient for touch events delivery frame rate correction.
 ///
 /// On promotion devices(eg: iPhone13 Pro), the delivery frame rate of touch events is 60HZ
 /// but the frame rate of rendering is 120HZ, which is different and will leads jitter and laggy.
 /// With this VSyncClient, it can correct the delivery frame rate of touch events to let it keep
 /// the same with frame rate of rendering.
-@property(nonatomic, retain) VSyncClient* touchRateCorrectionVSyncClient;
+@property(nonatomic, strong) VSyncClient* touchRateCorrectionVSyncClient;
 
 /*
  * Mouse and trackpad gesture recognizers
  */
 // Mouse and trackpad hover
-@property(nonatomic, retain)
+@property(nonatomic, strong)
     UIHoverGestureRecognizer* hoverGestureRecognizer API_AVAILABLE(ios(13.4));
 // Mouse wheel scrolling
-@property(nonatomic, retain)
+@property(nonatomic, strong)
     UIPanGestureRecognizer* discreteScrollingPanGestureRecognizer API_AVAILABLE(ios(13.4));
 // Trackpad and Magic Mouse scrolling
-@property(nonatomic, retain)
+@property(nonatomic, strong)
     UIPanGestureRecognizer* continuousScrollingPanGestureRecognizer API_AVAILABLE(ios(13.4));
 // Trackpad pinching
-@property(nonatomic, retain)
+@property(nonatomic, strong)
     UIPinchGestureRecognizer* pinchGestureRecognizer API_AVAILABLE(ios(13.4));
 // Trackpad rotating
-@property(nonatomic, retain)
+@property(nonatomic, strong)
     UIRotationGestureRecognizer* rotationGestureRecognizer API_AVAILABLE(ios(13.4));
 
-/**
- * Creates and registers plugins used by this view controller.
- */
+/// Creates and registers plugins used by this view controller.
 - (void)addInternalPlugins;
 - (void)deregisterNotifications;
+
+/// Called when the first frame has been rendered. Invokes any registered first-frame callback.
+- (void)onFirstFrameRendered;
+
+/// Handles updating viewport metrics on keyboard animation.
+- (void)handleKeyboardAnimationCallbackWithTargetTime:(fml::TimePoint)targetTime;
 @end
 
 @implementation FlutterViewController {
+  // TODO(cbracken): https://github.com/flutter/flutter/issues/137801
+  // Eliminate once we can use weak pointers in platform_view_ios.h.
   std::unique_ptr<fml::WeakNSObjectFactory<FlutterViewController>> _weakFactory;
-  fml::scoped_nsobject<FlutterEngine> _engine;
-
-  // We keep a separate reference to this and create it ahead of time because we want to be able to
-  // set up a shell along with its platform view before the view has to appear.
-  fml::scoped_nsobject<FlutterView> _flutterView;
-  fml::scoped_nsobject<UIView> _splashScreenView;
-  fml::ScopedBlock<void (^)(void)> _flutterViewRenderedCallback;
-  UIInterfaceOrientationMask _orientationPreferences;
-  UIStatusBarStyle _statusBarStyle;
+  FlutterEngine* _engine;
+
   flutter::ViewportMetrics _viewportMetrics;
-  BOOL _initialized;
-  BOOL _viewOpaque;
-  BOOL _engineNeedsLaunch;
-  fml::scoped_nsobject<NSMutableSet<NSNumber*>> _ongoingTouches;
-  // This scroll view is a workaround to accommodate iOS 13 and higher.  There isn't a way to get
-  // touches on the status bar to trigger scrolling to the top of a scroll view.  We place a
-  // UIScrollView with height zero and a content offset so we can get those events. See also:
-  // https://github.com/flutter/flutter/issues/35050
-  fml::scoped_nsobject<UIScrollView> _scrollView;
-  fml::scoped_nsobject<UIView> _keyboardAnimationView;
-  fml::scoped_nsobject<SpringAnimation> _keyboardSpringAnimation;
   MouseState _mouseState;
-  // Timestamp after which a scroll inertia cancel event should be inferred.
-  NSTimeInterval _scrollInertiaEventStartline;
-  // When an iOS app is running in emulation on an Apple Silicon Mac, trackpad input goes through
-  // a translation layer, and events are not received with precise deltas. Due to this, we can't
-  // rely on checking for a stationary trackpad event. Fortunately, AppKit will send an event of
-  // type UIEventTypeScroll following a scroll when inertia should stop. This field is needed to
-  // estimate if such an event represents the natural end of scrolling inertia or a user-initiated
-  // cancellation.
-  NSTimeInterval _scrollInertiaEventAppKitDeadline;
 }
 
+@synthesize viewOpaque = _viewOpaque;
 @synthesize displayingFlutterUI = _displayingFlutterUI;
 @synthesize prefersStatusBarHidden = _flutterPrefersStatusBarHidden;
 @dynamic viewIdentifier;
@@ -173,14 +184,16 @@ - (instancetype)initWithEngine:(FlutterEngine*)engine
                         "FlutterViewController at a time. Set FlutterEngine.viewController "
                         "to nil before attaching it to another FlutterViewController.";
     }
-    _engine.reset([engine retain]);
+    _engine = engine;
     _engineNeedsLaunch = NO;
-    _flutterView.reset([[FlutterView alloc] initWithDelegate:_engine
-                                                      opaque:self.isViewOpaque
-                                             enableWideGamut:engine.project.isWideGamutEnabled]);
+    _flutterView = [[FlutterView alloc] initWithDelegate:_engine
+                                                  opaque:self.isViewOpaque
+                                         enableWideGamut:engine.project.isWideGamutEnabled];
     _weakFactory = std::make_unique<fml::WeakNSObjectFactory<FlutterViewController>>(self);
-    _ongoingTouches.reset([[NSMutableSet alloc] init]);
+    _ongoingTouches = [[NSMutableSet alloc] init];
 
+    // TODO(cbracken): https://github.com/flutter/flutter/issues/157140
+    // Eliminate method calls in initializers and dealloc.
     [self performCommonViewControllerInitialization];
     [engine setViewController:self];
   }
@@ -193,6 +206,8 @@ - (instancetype)initWithProject:(FlutterDartProject*)project
                          bundle:(NSBundle*)nibBundle {
   self = [super initWithNibName:nibName bundle:nibBundle];
   if (self) {
+    // TODO(cbracken): https://github.com/flutter/flutter/issues/157140
+    // Eliminate method calls in initializers and dealloc.
     [self sharedSetupWithProject:project initialRoute:nil];
   }
 
@@ -205,6 +220,8 @@ - (instancetype)initWithProject:(FlutterDartProject*)project
                          bundle:(NSBundle*)nibBundle {
   self = [super initWithNibName:nibName bundle:nibBundle];
   if (self) {
+    // TODO(cbracken): https://github.com/flutter/flutter/issues/157140
+    // Eliminate method calls in initializers and dealloc.
     [self sharedSetupWithProject:project initialRoute:initialRoute];
   }
 
@@ -222,7 +239,7 @@ - (instancetype)initWithCoder:(NSCoder*)aDecoder {
 
 - (void)awakeFromNib {
   [super awakeFromNib];
-  if (!_engine) {
+  if (!self.engine) {
     [self sharedSetupWithProject:nil initialRoute:nil];
   }
 }
@@ -236,28 +253,29 @@ - (void)sharedSetupWithProject:(nullable FlutterDartProject*)project
   // Need the project to get settings for the view. Initializing it here means
   // the Engine class won't initialize it later.
   if (!project) {
-    project = [[[FlutterDartProject alloc] init] autorelease];
+    project = [[FlutterDartProject alloc] init];
   }
   FlutterView.forceSoftwareRendering = project.settings.enable_software_rendering;
   _weakFactory = std::make_unique<fml::WeakNSObjectFactory<FlutterViewController>>(self);
-  auto engine = fml::scoped_nsobject<FlutterEngine>{[[FlutterEngine alloc]
-                initWithName:@"io.flutter"
-                     project:project
-      allowHeadlessExecution:self.engineAllowHeadlessExecution
-          restorationEnabled:[self restorationIdentifier] != nil]};
-
+  FlutterEngine* engine = [[FlutterEngine alloc] initWithName:@"io.flutter"
+                                                      project:project
+                                       allowHeadlessExecution:self.engineAllowHeadlessExecution
+                                           restorationEnabled:self.restorationIdentifier != nil];
   if (!engine) {
     return;
   }
 
   _viewOpaque = YES;
   _engine = engine;
-  _flutterView.reset([[FlutterView alloc] initWithDelegate:_engine
-                                                    opaque:self.isViewOpaque
-                                           enableWideGamut:project.isWideGamutEnabled]);
-  [_engine.get() createShell:nil libraryURI:nil initialRoute:initialRoute];
+  _flutterView = [[FlutterView alloc] initWithDelegate:_engine
+                                                opaque:_viewOpaque
+                                       enableWideGamut:project.isWideGamutEnabled];
+  [_engine createShell:nil libraryURI:nil initialRoute:initialRoute];
   _engineNeedsLaunch = YES;
-  _ongoingTouches.reset([[NSMutableSet alloc] init]);
+  _ongoingTouches = [[NSMutableSet alloc] init];
+
+  // TODO(cbracken): https://github.com/flutter/flutter/issues/157140
+  // Eliminate method calls in initializers and dealloc.
   [self loadDefaultSplashScreenView];
   [self performCommonViewControllerInitialization];
 }
@@ -268,9 +286,9 @@ - (BOOL)isViewOpaque {
 
 - (void)setViewOpaque:(BOOL)value {
   _viewOpaque = value;
-  if (_flutterView.get().layer.opaque != value) {
-    _flutterView.get().layer.opaque = value;
-    [_flutterView.get().layer setNeedsLayout];
+  if (self.flutterView.layer.opaque != value) {
+    self.flutterView.layer.opaque = value;
+    [self.flutterView.layer setNeedsLayout];
   }
 }
 
@@ -282,15 +300,16 @@ - (void)performCommonViewControllerInitialization {
   }
 
   _initialized = YES;
-
   _orientationPreferences = UIInterfaceOrientationMaskAll;
   _statusBarStyle = UIStatusBarStyleDefault;
 
+  // TODO(cbracken): https://github.com/flutter/flutter/issues/157140
+  // Eliminate method calls in initializers and dealloc.
   [self setUpNotificationCenterObservers];
 }
 
 - (FlutterEngine*)engine {
-  return _engine.get();
+  return _engine;
 }
 
 - (fml::WeakNSObject<FlutterViewController>)getWeakNSObject {
@@ -447,15 +466,15 @@ - (void)setUpApplicationLifecycleNotifications:(NSNotificationCenter*)center {
 }
 
 - (void)setInitialRoute:(NSString*)route {
-  [[_engine.get() navigationChannel] invokeMethod:@"setInitialRoute" arguments:route];
+  [self.engine.navigationChannel invokeMethod:@"setInitialRoute" arguments:route];
 }
 
 - (void)popRoute {
-  [[_engine.get() navigationChannel] invokeMethod:@"popRoute" arguments:nil];
+  [self.engine.navigationChannel invokeMethod:@"popRoute" arguments:nil];
 }
 
 - (void)pushRoute:(NSString*)route {
-  [[_engine.get() navigationChannel] invokeMethod:@"pushRoute" arguments:route];
+  [self.engine.navigationChannel invokeMethod:@"pushRoute" arguments:route];
 }
 
 #pragma mark - Loading the view
@@ -465,7 +484,7 @@ - (void)pushRoute:(NSString*)route {
     return existing_view;
   }
 
-  auto placeholder = [[[UIView alloc] init] autorelease];
+  auto placeholder = [[UIView alloc] init];
 
   placeholder.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
   if (@available(iOS 13.0, *)) {
@@ -479,7 +498,7 @@ - (void)pushRoute:(NSString*)route {
   // Otherwise, a spurious warning will be shown in cases where an engine cannot be initialized for
   // other reasons.
   if (flutter::GetTracingResult() == flutter::TracingResult::kDisabled) {
-    auto messageLabel = [[[UILabel alloc] init] autorelease];
+    auto messageLabel = [[UILabel alloc] init];
     messageLabel.numberOfLines = 0u;
     messageLabel.textAlignment = NSTextAlignmentCenter;
     messageLabel.autoresizingMask =
@@ -495,11 +514,13 @@ - (void)pushRoute:(NSString*)route {
 }
 
 - (void)loadView {
-  self.view = GetViewOrPlaceholder(_flutterView.get());
+  self.view = GetViewOrPlaceholder(self.flutterView);
   self.view.multipleTouchEnabled = YES;
   self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
 
   [self installSplashScreenViewIfNecessary];
+
+  // Create and set up the scroll view.
   UIScrollView* scrollView = [[UIScrollView alloc] init];
   scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
   // The color shouldn't matter since it is offscreen.
@@ -509,8 +530,9 @@ - (void)loadView {
   scrollView.contentSize = CGSizeMake(kScrollViewContentSize, kScrollViewContentSize);
   // This is an arbitrary offset that is not CGPointZero.
   scrollView.contentOffset = CGPointMake(kScrollViewContentSize, kScrollViewContentSize);
+
   [self.view addSubview:scrollView];
-  _scrollView.reset(scrollView);
+  self.scrollView = scrollView;
 }
 
 - (flutter::PointerData)generatePointerDataForFake {
@@ -539,14 +561,14 @@ static void SendFakeTouchEvent(UIScreen* screen,
 }
 
 - (BOOL)scrollViewShouldScrollToTop:(UIScrollView*)scrollView {
-  if (!_engine) {
+  if (!self.engine) {
     return NO;
   }
   CGPoint statusBarPoint = CGPointZero;
-  UIScreen* screen = [self flutterScreenIfViewLoaded];
+  UIScreen* screen = self.flutterScreenIfViewLoaded;
   if (screen) {
-    SendFakeTouchEvent(screen, _engine.get(), statusBarPoint, flutter::PointerData::Change::kDown);
-    SendFakeTouchEvent(screen, _engine.get(), statusBarPoint, flutter::PointerData::Change::kUp);
+    SendFakeTouchEvent(screen, self.engine, statusBarPoint, flutter::PointerData::Change::kDown);
+    SendFakeTouchEvent(screen, self.engine, statusBarPoint, flutter::PointerData::Change::kUp);
   }
   return NO;
 }
@@ -556,9 +578,9 @@ - (BOOL)scrollViewShouldScrollToTop:(UIScrollView*)scrollView {
 - (void)installSplashScreenViewIfNecessary {
   // Show the launch screen view again on top of the FlutterView if available.
   // This launch screen view will be removed once the first Flutter frame is rendered.
-  if (_splashScreenView && (self.isBeingPresented || self.isMovingToParentViewController)) {
-    [_splashScreenView.get() removeFromSuperview];
-    _splashScreenView.reset();
+  if (self.splashScreenView && (self.isBeingPresented || self.isMovingToParentViewController)) {
+    [self.splashScreenView removeFromSuperview];
+    self.splashScreenView = nil;
     return;
   }
 
@@ -590,60 +612,58 @@ - (void)setDisplayingFlutterUI:(BOOL)displayingFlutterUI {
 
 - (void)callViewRenderedCallback {
   self.displayingFlutterUI = YES;
-  if (_flutterViewRenderedCallback != nil) {
-    _flutterViewRenderedCallback.get()();
-    _flutterViewRenderedCallback.reset();
+  if (self.flutterViewRenderedCallback) {
+    self.flutterViewRenderedCallback();
+    self.flutterViewRenderedCallback = nil;
   }
 }
 
-- (void)removeSplashScreenView:(dispatch_block_t _Nullable)onComplete {
-  NSAssert(_splashScreenView, @"The splash screen view must not be null");
-  UIView* splashScreen = [_splashScreenView.get() retain];
-  _splashScreenView.reset();
+- (void)removeSplashScreenWithCompletion:(dispatch_block_t _Nullable)onComplete {
+  NSAssert(self.splashScreenView, @"The splash screen view must not be nil");
+  UIView* splashScreen = self.splashScreenView;
+  // setSplashScreenView calls this method. Assign directly to ivar to avoid an infinite loop.
+  _splashScreenView = nil;
   [UIView animateWithDuration:0.2
       animations:^{
         splashScreen.alpha = 0;
       }
       completion:^(BOOL finished) {
         [splashScreen removeFromSuperview];
-        [splashScreen release];
         if (onComplete) {
           onComplete();
         }
       }];
 }
 
+- (void)onFirstFrameRendered {
+  if (self.splashScreenView) {
+    __weak FlutterViewController* weakSelf = self;
+    [self removeSplashScreenWithCompletion:^{
+      [weakSelf callViewRenderedCallback];
+    }];
+  } else {
+    [self callViewRenderedCallback];
+  }
+}
+
 - (void)installFirstFrameCallback {
-  if (!_engine) {
+  if (!self.engine) {
     return;
   }
 
-  fml::WeakPtr<flutter::PlatformViewIOS> weakPlatformView = [_engine.get() platformView];
+  fml::WeakPtr<flutter::PlatformViewIOS> weakPlatformView = self.engine.platformView;
   if (!weakPlatformView) {
     return;
   }
 
   // Start on the platform thread.
-  weakPlatformView->SetNextFrameCallback([weakSelf = [self getWeakNSObject],
-                                          platformTaskRunner = [_engine.get() platformTaskRunner],
-                                          rasterTaskRunner = [_engine.get() rasterTaskRunner]]() {
+  __weak FlutterViewController* weakSelf = self;
+  weakPlatformView->SetNextFrameCallback([weakSelf,
+                                          platformTaskRunner = self.engine.platformTaskRunner,
+                                          rasterTaskRunner = self.engine.rasterTaskRunner]() {
     FML_DCHECK(rasterTaskRunner->RunsTasksOnCurrentThread());
     // Get callback on raster thread and jump back to platform thread.
-    platformTaskRunner->PostTask([weakSelf]() {
-      if (weakSelf) {
-        fml::scoped_nsobject<FlutterViewController> flutterViewController(
-            [(FlutterViewController*)weakSelf.get() retain]);
-        if (flutterViewController) {
-          if (flutterViewController.get()->_splashScreenView) {
-            [flutterViewController removeSplashScreenView:^{
-              [flutterViewController callViewRenderedCallback];
-            }];
-          } else {
-            [flutterViewController callViewRenderedCallback];
-          }
-        }
-      }
-    });
+    platformTaskRunner->PostTask([weakSelf]() { [weakSelf onFirstFrameRendered]; });
   });
 }
 
@@ -655,21 +675,6 @@ - (int64_t)viewIdentifier {
   return flutter::kFlutterImplicitViewId;
 }
 
-- (UIView*)splashScreenView {
-  if (!_splashScreenView) {
-    return nil;
-  }
-  return _splashScreenView.get();
-}
-
-- (UIView*)keyboardAnimationView {
-  return _keyboardAnimationView.get();
-}
-
-- (SpringAnimation*)keyboardSpringAnimation {
-  return _keyboardSpringAnimation.get();
-}
-
 - (BOOL)loadDefaultSplashScreenView {
   NSString* launchscreenName =
       [[[NSBundle mainBundle] infoDictionary] objectForKey:@"UILaunchStoryboardName"];
@@ -716,27 +721,31 @@ - (UIView*)splashScreenFromXib:(NSString*)name {
 }
 
 - (void)setSplashScreenView:(UIView*)view {
+  if (view == _splashScreenView) {
+    return;
+  }
+
+  // Special case: user wants to remove the splash screen view.
   if (!view) {
-    // Special case: user wants to remove the splash screen view.
     if (_splashScreenView) {
-      [self removeSplashScreenView:nil];
+      [self removeSplashScreenWithCompletion:nil];
     }
     return;
   }
 
-  _splashScreenView.reset([view retain]);
-  _splashScreenView.get().autoresizingMask =
+  _splashScreenView = view;
+  _splashScreenView.autoresizingMask =
       UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
 }
 
 - (void)setFlutterViewDidRenderCallback:(void (^)(void))callback {
-  _flutterViewRenderedCallback.reset(callback, fml::scoped_policy::OwnershipPolicy::kRetain);
+  _flutterViewRenderedCallback = callback;
 }
 
 #pragma mark - Surface creation and teardown updates
 
 - (void)surfaceUpdated:(BOOL)appeared {
-  if (!_engine) {
+  if (!self.engine) {
     return;
   }
 
@@ -744,14 +753,14 @@ - (void)surfaceUpdated:(BOOL)appeared {
   // thread.
   if (appeared) {
     [self installFirstFrameCallback];
-    [_engine.get() platformViewsController]->SetFlutterView(_flutterView.get());
-    [_engine.get() platformViewsController]->SetFlutterViewController(self);
-    [_engine.get() iosPlatformView]->NotifyCreated();
+    [self.engine platformViewsController]->SetFlutterView(self.flutterView);
+    [self.engine platformViewsController]->SetFlutterViewController(self);
+    [self.engine iosPlatformView]->NotifyCreated();
   } else {
     self.displayingFlutterUI = NO;
-    [_engine.get() iosPlatformView]->NotifyDestroyed();
-    [_engine.get() platformViewsController]->SetFlutterView(nullptr);
-    [_engine.get() platformViewsController]->SetFlutterViewController(nullptr);
+    [self.engine iosPlatformView]->NotifyDestroyed();
+    [self.engine platformViewsController]->SetFlutterView(nullptr);
+    [self.engine platformViewsController]->SetFlutterViewController(nullptr);
   }
 }
 
@@ -760,12 +769,12 @@ - (void)surfaceUpdated:(BOOL)appeared {
 - (void)viewDidLoad {
   TRACE_EVENT0("flutter", "viewDidLoad");
 
-  if (_engine && _engineNeedsLaunch) {
-    [_engine.get() launchEngine:nil libraryURI:nil entrypointArgs:nil];
-    [_engine.get() setViewController:self];
-    _engineNeedsLaunch = NO;
-  } else if ([_engine.get() viewController] == self) {
-    [_engine.get() attachView];
+  if (self.engine && self.engineNeedsLaunch) {
+    [self.engine launchEngine:nil libraryURI:nil entrypointArgs:nil];
+    [self.engine setViewController:self];
+    self.engineNeedsLaunch = NO;
+  } else if (self.engine.viewController == self) {
+    [self.engine attachView];
   }
 
   // Register internal plugins.
@@ -778,7 +787,7 @@ - (void)viewDidLoad {
     _hoverGestureRecognizer =
         [[UIHoverGestureRecognizer alloc] initWithTarget:self action:@selector(hoverEvent:)];
     _hoverGestureRecognizer.delegate = self;
-    [_flutterView.get() addGestureRecognizer:_hoverGestureRecognizer];
+    [self.flutterView addGestureRecognizer:_hoverGestureRecognizer];
 
     _discreteScrollingPanGestureRecognizer =
         [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(discreteScrollEvent:)];
@@ -789,47 +798,45 @@ - (void)viewDidLoad {
     // than touch events, so they will still be received.
     _discreteScrollingPanGestureRecognizer.allowedTouchTypes = @[];
     _discreteScrollingPanGestureRecognizer.delegate = self;
-    [_flutterView.get() addGestureRecognizer:_discreteScrollingPanGestureRecognizer];
+    [self.flutterView addGestureRecognizer:_discreteScrollingPanGestureRecognizer];
     _continuousScrollingPanGestureRecognizer =
         [[UIPanGestureRecognizer alloc] initWithTarget:self
                                                 action:@selector(continuousScrollEvent:)];
     _continuousScrollingPanGestureRecognizer.allowedScrollTypesMask = UIScrollTypeMaskContinuous;
     _continuousScrollingPanGestureRecognizer.allowedTouchTypes = @[];
     _continuousScrollingPanGestureRecognizer.delegate = self;
-    [_flutterView.get() addGestureRecognizer:_continuousScrollingPanGestureRecognizer];
+    [self.flutterView addGestureRecognizer:_continuousScrollingPanGestureRecognizer];
     _pinchGestureRecognizer =
         [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchEvent:)];
     _pinchGestureRecognizer.allowedTouchTypes = @[];
     _pinchGestureRecognizer.delegate = self;
-    [_flutterView.get() addGestureRecognizer:_pinchGestureRecognizer];
+    [self.flutterView addGestureRecognizer:_pinchGestureRecognizer];
     _rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] init];
     _rotationGestureRecognizer.allowedTouchTypes = @[];
     _rotationGestureRecognizer.delegate = self;
-    [_flutterView.get() addGestureRecognizer:_rotationGestureRecognizer];
+    [self.flutterView addGestureRecognizer:_rotationGestureRecognizer];
   }
 
   [super viewDidLoad];
 }
 
 - (void)addInternalPlugins {
-  self.keyboardManager = [[[FlutterKeyboardManager alloc] init] autorelease];
-  fml::WeakNSObject<FlutterViewController> weakSelf = [self getWeakNSObject];
+  self.keyboardManager = [[FlutterKeyboardManager alloc] init];
+  __weak FlutterViewController* weakSelf = self;
   FlutterSendKeyEvent sendEvent =
       ^(const FlutterKeyEvent& event, FlutterKeyEventCallback callback, void* userData) {
-        if (weakSelf) {
-          [weakSelf.get()->_engine.get() sendKeyEvent:event callback:callback userData:userData];
-        }
+        [weakSelf.engine sendKeyEvent:event callback:callback userData:userData];
       };
-  [self.keyboardManager addPrimaryResponder:[[[FlutterEmbedderKeyResponder alloc]
-                                                initWithSendEvent:sendEvent] autorelease]];
-  FlutterChannelKeyResponder* responder = [[[FlutterChannelKeyResponder alloc]
-      initWithChannel:self.engine.keyEventChannel] autorelease];
+  [self.keyboardManager
+      addPrimaryResponder:[[FlutterEmbedderKeyResponder alloc] initWithSendEvent:sendEvent]];
+  FlutterChannelKeyResponder* responder =
+      [[FlutterChannelKeyResponder alloc] initWithChannel:self.engine.keyEventChannel];
   [self.keyboardManager addPrimaryResponder:responder];
   FlutterTextInputPlugin* textInputPlugin = self.engine.textInputPlugin;
   if (textInputPlugin != nil) {
     [self.keyboardManager addSecondaryResponder:textInputPlugin];
   }
-  if ([_engine.get() viewController] == self) {
+  if (self.engine.viewController == self) {
     [textInputPlugin setUpIndirectScribbleInteraction:self];
   }
 }
@@ -840,7 +847,7 @@ - (void)removeInternalPlugins {
 
 - (void)viewWillAppear:(BOOL)animated {
   TRACE_EVENT0("flutter", "viewWillAppear");
-  if ([_engine.get() viewController] == self) {
+  if (self.engine.viewController == self) {
     // Send platform settings to Flutter, e.g., platform brightness.
     [self onUserSettingsChanged:nil];
 
@@ -849,8 +856,8 @@ - (void)viewWillAppear:(BOOL)animated {
     if (_viewportMetrics.physical_width) {
       [self surfaceUpdated:YES];
     }
-    [[_engine.get() lifecycleChannel] sendMessage:@"AppLifecycleState.inactive"];
-    [[_engine.get() restorationPlugin] markRestorationComplete];
+    [self.engine.lifecycleChannel sendMessage:@"AppLifecycleState.inactive"];
+    [self.engine.restorationPlugin markRestorationComplete];
   }
 
   [super viewWillAppear:animated];
@@ -858,7 +865,7 @@ - (void)viewWillAppear:(BOOL)animated {
 
 - (void)viewDidAppear:(BOOL)animated {
   TRACE_EVENT0("flutter", "viewDidAppear");
-  if ([_engine.get() viewController] == self) {
+  if (self.engine.viewController == self) {
     [self onUserSettingsChanged:nil];
     [self onAccessibilityStatusChanged:nil];
     BOOL stateIsActive = YES;
@@ -871,7 +878,7 @@ - (void)viewDidAppear:(BOOL)animated {
     stateIsActive = UIApplication.sharedApplication.applicationState == UIApplicationStateActive;
 #endif
     if (stateIsActive) {
-      [[_engine.get() lifecycleChannel] sendMessage:@"AppLifecycleState.resumed"];
+      [self.engine.lifecycleChannel sendMessage:@"AppLifecycleState.resumed"];
     }
   }
   [super viewDidAppear:animated];
@@ -879,21 +886,21 @@ - (void)viewDidAppear:(BOOL)animated {
 
 - (void)viewWillDisappear:(BOOL)animated {
   TRACE_EVENT0("flutter", "viewWillDisappear");
-  if ([_engine.get() viewController] == self) {
-    [[_engine.get() lifecycleChannel] sendMessage:@"AppLifecycleState.inactive"];
+  if (self.engine.viewController == self) {
+    [self.engine.lifecycleChannel sendMessage:@"AppLifecycleState.inactive"];
   }
   [super viewWillDisappear:animated];
 }
 
 - (void)viewDidDisappear:(BOOL)animated {
   TRACE_EVENT0("flutter", "viewDidDisappear");
-  if ([_engine.get() viewController] == self) {
+  if (self.engine.viewController == self) {
     [self invalidateKeyboardAnimationVSyncClient];
     [self ensureViewportMetricsIsCorrect];
     [self surfaceUpdated:NO];
-    [[_engine.get() lifecycleChannel] sendMessage:@"AppLifecycleState.paused"];
+    [self.engine.lifecycleChannel sendMessage:@"AppLifecycleState.paused"];
     [self flushOngoingTouches];
-    [_engine.get() notifyLowMemory];
+    [self.engine notifyLowMemory];
   }
 
   [super viewDidDisappear:animated];
@@ -917,24 +924,30 @@ - (void)viewWillTransitionToSize:(CGSize)size
     return;
   }
 
+  __weak FlutterViewController* weakSelf = self;
   _shouldIgnoreViewportMetricsUpdatesDuringRotation = YES;
   dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
                                static_cast<int64_t>(transitionDuration / 2.0 * NSEC_PER_SEC)),
                  dispatch_get_main_queue(), ^{
+                   FlutterViewController* strongSelf = weakSelf;
+                   if (!strongSelf) {
+                     return;
+                   }
+
                    // `viewWillTransitionToSize` is only called after the previous rotation is
                    // complete. So there won't be race condition for this flag.
-                   _shouldIgnoreViewportMetricsUpdatesDuringRotation = NO;
-                   [self updateViewportMetricsIfNeeded];
+                   strongSelf.shouldIgnoreViewportMetricsUpdatesDuringRotation = NO;
+                   [strongSelf updateViewportMetricsIfNeeded];
                  });
 }
 
 - (void)flushOngoingTouches {
-  if (_engine && _ongoingTouches.get().count > 0) {
-    auto packet = std::make_unique<flutter::PointerDataPacket>(_ongoingTouches.get().count);
+  if (self.engine && self.ongoingTouches.count > 0) {
+    auto packet = std::make_unique<flutter::PointerDataPacket>(self.ongoingTouches.count);
     size_t pointer_index = 0;
     // If the view controller is going away, we want to flush cancel all the ongoing
     // touches to the framework so nothing gets orphaned.
-    for (NSNumber* device in _ongoingTouches.get()) {
+    for (NSNumber* device in self.ongoingTouches) {
       // Create fake PointerData to balance out each previously started one for the framework.
       flutter::PointerData pointer_data = [self generatePointerDataForFake];
 
@@ -954,8 +967,8 @@ - (void)flushOngoingTouches {
       packet->SetPointerData(pointer_index++, pointer_data);
     }
 
-    [_ongoingTouches removeAllObjects];
-    [_engine.get() dispatchPointerDataPacket:std::move(packet)];
+    [self.ongoingTouches removeAllObjects];
+    [self.engine dispatchPointerDataPacket:std::move(packet)];
   }
 }
 
@@ -971,23 +984,22 @@ - (void)dealloc {
   // before any other members are destroyed.
   _weakFactory.reset();
 
+  // TODO(cbracken): https://github.com/flutter/flutter/issues/157140
+  // Eliminate method calls in initializers and dealloc.
   [self removeInternalPlugins];
   [self deregisterNotifications];
 
   [self invalidateKeyboardAnimationVSyncClient];
   [self invalidateTouchRateCorrectionVSyncClient];
-  _scrollView.get().delegate = nil;
+
+  // TODO(cbracken): https://github.com/flutter/flutter/issues/156222
+  // Ensure all delegates are weak and remove this.
+  _scrollView.delegate = nil;
   _hoverGestureRecognizer.delegate = nil;
-  [_hoverGestureRecognizer release];
   _discreteScrollingPanGestureRecognizer.delegate = nil;
-  [_discreteScrollingPanGestureRecognizer release];
   _continuousScrollingPanGestureRecognizer.delegate = nil;
-  [_continuousScrollingPanGestureRecognizer release];
   _pinchGestureRecognizer.delegate = nil;
-  [_pinchGestureRecognizer release];
   _rotationGestureRecognizer.delegate = nil;
-  [_rotationGestureRecognizer release];
-  [super dealloc];
 }
 
 #pragma mark - Application lifecycle notifications
@@ -1081,7 +1093,7 @@ - (void)goToApplicationLifecycle:(nonnull NSString*)state {
   // Accessing self.view will create the view. Instead use viewIfLoaded
   // to check whether the view is attached to window.
   if (self.viewIfLoaded.window) {
-    [[_engine.get() lifecycleChannel] sendMessage:state];
+    [self.engine.lifecycleChannel sendMessage:state];
   }
 }
 
@@ -1133,7 +1145,7 @@ - (void)goToApplicationLifecycle:(nonnull NSString*)state {
 - (void)dispatchTouches:(NSSet*)touches
     pointerDataChangeOverride:(flutter::PointerData::Change*)overridden_change
                         event:(UIEvent*)event {
-  if (!_engine) {
+  if (!self.engine) {
     return;
   }
 
@@ -1167,7 +1179,7 @@ - (void)dispatchTouches:(NSSet*)touches
   // Activate or pause the correction of delivery frame rate of touch events.
   [self triggerTouchRateCorrectionIfNeeded:touches];
 
-  const CGFloat scale = [self flutterScreenIfViewLoaded].scale;
+  const CGFloat scale = self.flutterScreenIfViewLoaded.scale;
   auto packet =
       std::make_unique<flutter::PointerDataPacket>(touches.count + touches_to_remove_count);
 
@@ -1207,11 +1219,11 @@ - (void)dispatchTouches:(NSSet*)touches
     // if the view controller goes away.
     switch (pointer_data.change) {
       case flutter::PointerData::Change::kDown:
-        [_ongoingTouches addObject:deviceKey];
+        [self.ongoingTouches addObject:deviceKey];
         break;
       case flutter::PointerData::Change::kCancel:
       case flutter::PointerData::Change::kUp:
-        [_ongoingTouches removeObject:deviceKey];
+        [self.ongoingTouches removeObject:deviceKey];
         break;
       case flutter::PointerData::Change::kHover:
       case flutter::PointerData::Change::kMove:
@@ -1290,7 +1302,7 @@ - (void)dispatchTouches:(NSSet*)touches
     }
   }
 
-  [_engine.get() dispatchPointerDataPacket:std::move(packet)];
+  [self.engine dispatchPointerDataPacket:std::move(packet)];
 }
 
 - (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event {
@@ -1331,7 +1343,7 @@ - (void)createTouchRateCorrectionVSyncClientIfNeeded {
     return;
   }
 
-  flutter::Shell& shell = [_engine.get() shell];
+  flutter::Shell& shell = self.engine.shell;
   auto callback = [](std::unique_ptr<flutter::FrameTimingsRecorder> recorder) {
     // Do nothing in this block. Just trigger system to callback touch events with correct rate.
   };
@@ -1358,7 +1370,7 @@ - (void)triggerTouchRateCorrectionIfNeeded:(NSSet*)touches {
     }
   }
 
-  if (isUserInteracting && [_engine.get() viewController] == self) {
+  if (isUserInteracting && self.engine.viewController == self) {
     [_touchRateCorrectionVSyncClient await];
   } else {
     [_touchRateCorrectionVSyncClient pause];
@@ -1367,7 +1379,6 @@ - (void)triggerTouchRateCorrectionIfNeeded:(NSSet*)touches {
 
 - (void)invalidateTouchRateCorrectionVSyncClient {
   [_touchRateCorrectionVSyncClient invalidate];
-  [_touchRateCorrectionVSyncClient release];
   _touchRateCorrectionVSyncClient = nil;
 }
 
@@ -1377,18 +1388,18 @@ - (void)updateViewportMetricsIfNeeded {
   if (_shouldIgnoreViewportMetricsUpdatesDuringRotation) {
     return;
   }
-  if ([_engine.get() viewController] == self) {
-    [_engine.get() updateViewportMetrics:_viewportMetrics];
+  if (self.engine.viewController == self) {
+    [self.engine updateViewportMetrics:_viewportMetrics];
   }
 }
 
 - (void)viewDidLayoutSubviews {
   CGRect viewBounds = self.view.bounds;
-  CGFloat scale = [self flutterScreenIfViewLoaded].scale;
+  CGFloat scale = self.flutterScreenIfViewLoaded.scale;
 
   // Purposefully place this not visible.
-  _scrollView.get().frame = CGRectMake(0.0, 0.0, viewBounds.size.width, 0.0);
-  _scrollView.get().contentOffset = CGPointMake(kScrollViewContentSize, kScrollViewContentSize);
+  self.scrollView.frame = CGRectMake(0.0, 0.0, viewBounds.size.width, 0.0);
+  self.scrollView.contentOffset = CGPointMake(kScrollViewContentSize, kScrollViewContentSize);
 
   // First time since creation that the dimensions of its view is known.
   bool firstViewBoundsUpdate = !_viewportMetrics.physical_width;
@@ -1413,10 +1424,10 @@ - (void)viewDidLayoutSubviews {
 
   // This must run after updateViewportMetrics so that the surface creation tasks are queued after
   // the viewport metrics update tasks.
-  if (firstViewBoundsUpdate && applicationOrSceneIsActive && _engine) {
+  if (firstViewBoundsUpdate && applicationOrSceneIsActive && self.engine) {
     [self surfaceUpdated:YES];
 
-    flutter::Shell& shell = [_engine.get() shell];
+    flutter::Shell& shell = self.engine.shell;
     fml::TimeDelta waitTime =
 #if FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_DEBUG
         fml::TimeDelta::FromMilliseconds(200);
@@ -1439,7 +1450,7 @@ - (void)viewSafeAreaInsetsDidChange {
 
 // Set _viewportMetrics physical size.
 - (void)setViewportMetricsSize {
-  UIScreen* screen = [self flutterScreenIfViewLoaded];
+  UIScreen* screen = self.flutterScreenIfViewLoaded;
   if (!screen) {
     return;
   }
@@ -1453,7 +1464,7 @@ - (void)setViewportMetricsSize {
 //
 // Viewport paddings represent the iOS safe area insets.
 - (void)setViewportMetricsPaddings {
-  UIScreen* screen = [self flutterScreenIfViewLoaded];
+  UIScreen* screen = self.flutterScreenIfViewLoaded;
   if (!screen) {
     return;
   }
@@ -1525,8 +1536,8 @@ - (void)handleKeyboardNotification:(NSNotification*)notification {
 
   if (!keyboardAnimationIsCompounding) {
     [self startKeyBoardAnimation:duration];
-  } else if ([self keyboardSpringAnimation]) {
-    [self keyboardSpringAnimation].toValue = self.targetViewInsetBottom;
+  } else if (self.keyboardSpringAnimation) {
+    self.keyboardSpringAnimation.toValue = self.targetViewInsetBottom;
   }
 }
 
@@ -1587,11 +1598,7 @@ - (BOOL)isKeyboardNotificationForDifferentView:(NSNotification*)notification {
   if (isLocal && ![isLocal boolValue]) {
     return YES;
   }
-  // Engine’s viewController is not current viewController.
-  if ([_engine.get() viewController] != self) {
-    return YES;
-  }
-  return NO;
+  return self.engine.viewController != self;
 }
 
 - (FlutterKeyboardMode)calculateKeyboardAttachMode:(NSNotification*)notification {
@@ -1619,7 +1626,7 @@ - (FlutterKeyboardMode)calculateKeyboardAttachMode:(NSNotification*)notification
     return FlutterKeyboardModeHidden;
   }
 
-  CGRect screenRect = [self flutterScreenIfViewLoaded].bounds;
+  CGRect screenRect = self.flutterScreenIfViewLoaded.bounds;
   CGRect adjustedKeyboardFrame = keyboardFrame;
   adjustedKeyboardFrame.origin.y += [self calculateMultitaskingAdjustment:screenRect
                                                             keyboardFrame:keyboardFrame];
@@ -1659,7 +1666,7 @@ - (CGFloat)calculateMultitaskingAdjustment:(CGRect)screenRect keyboardFrame:(CGR
     }
     CGRect viewRectRelativeToScreen =
         [self.viewIfLoaded convertRect:self.viewIfLoaded.frame
-                     toCoordinateSpace:[self flutterScreenIfViewLoaded].coordinateSpace];
+                     toCoordinateSpace:self.flutterScreenIfViewLoaded.coordinateSpace];
     CGFloat viewBottom = CGRectGetMaxY(viewRectRelativeToScreen);
     CGFloat offset = screenHeight - viewBottom;
     if (offset > 0) {
@@ -1675,14 +1682,14 @@ - (CGFloat)calculateKeyboardInset:(CGRect)keyboardFrame keyboardMode:(NSInteger)
     // Calculate how much of the keyboard intersects with the view.
     CGRect viewRectRelativeToScreen =
         [self.viewIfLoaded convertRect:self.viewIfLoaded.frame
-                     toCoordinateSpace:[self flutterScreenIfViewLoaded].coordinateSpace];
+                     toCoordinateSpace:self.flutterScreenIfViewLoaded.coordinateSpace];
     CGRect intersection = CGRectIntersection(keyboardFrame, viewRectRelativeToScreen);
     CGFloat portionOfKeyboardInView = CGRectGetHeight(intersection);
 
     // The keyboard is treated as an inset since we want to effectively reduce the window size by
     // the keyboard height. The Dart side will compute a value accounting for the keyboard-consuming
     // bottom padding.
-    CGFloat scale = [self flutterScreenIfViewLoaded].scale;
+    CGFloat scale = self.flutterScreenIfViewLoaded.scale;
     return portionOfKeyboardInView * scale;
   }
   return 0;
@@ -1696,21 +1703,21 @@ - (void)startKeyBoardAnimation:(NSTimeInterval)duration {
 
   // When this method is called for the first time,
   // initialize the keyboardAnimationView to get animation interpolation during animation.
-  if ([self keyboardAnimationView] == nil) {
+  if (!self.keyboardAnimationView) {
     UIView* keyboardAnimationView = [[UIView alloc] init];
-    [keyboardAnimationView setHidden:YES];
-    _keyboardAnimationView.reset(keyboardAnimationView);
+    keyboardAnimationView.hidden = YES;
+    self.keyboardAnimationView = keyboardAnimationView;
   }
 
-  if ([self keyboardAnimationView].superview == nil) {
-    [self.view addSubview:[self keyboardAnimationView]];
+  if (!self.keyboardAnimationView.superview) {
+    [self.view addSubview:self.keyboardAnimationView];
   }
 
   // Remove running animation when start another animation.
-  [[self keyboardAnimationView].layer removeAllAnimations];
+  [self.keyboardAnimationView.layer removeAllAnimations];
 
   // Set animation begin value and DisplayLink tracking values.
-  [self keyboardAnimationView].frame =
+  self.keyboardAnimationView.frame =
       CGRectMake(0, _viewportMetrics.physical_view_inset_bottom, 0, 0);
   self.keyboardAnimationStartTime = fml::TimePoint().Now();
   self.originalViewInsetBottom = _viewportMetrics.physical_view_inset_bottom;
@@ -1718,74 +1725,40 @@ - (void)startKeyBoardAnimation:(NSTimeInterval)duration {
   // Invalidate old vsync client if old animation is not completed.
   [self invalidateKeyboardAnimationVSyncClient];
 
-  fml::WeakNSObject<FlutterViewController> weakSelf = [self getWeakNSObject];
-  FlutterKeyboardAnimationCallback keyboardAnimationCallback = ^(
-      fml::TimePoint keyboardAnimationTargetTime) {
-    if (!weakSelf) {
-      return;
-    }
-    fml::scoped_nsobject<FlutterViewController> flutterViewController(
-        [(FlutterViewController*)weakSelf.get() retain]);
-    if (!flutterViewController) {
-      return;
-    }
-
-    // If the view controller's view is not loaded, bail out.
-    if (!flutterViewController.get().isViewLoaded) {
-      return;
-    }
-    // If the view for tracking keyboard animation is nil, means it is not
-    // created, bail out.
-    if ([flutterViewController keyboardAnimationView] == nil) {
-      return;
-    }
-    // If keyboardAnimationVSyncClient is nil, means the animation ends.
-    // And should bail out.
-    if (flutterViewController.get().keyboardAnimationVSyncClient == nil) {
-      return;
-    }
-
-    if ([flutterViewController keyboardAnimationView].superview == nil) {
-      // Ensure the keyboardAnimationView is in view hierarchy when animation running.
-      [flutterViewController.get().view addSubview:[flutterViewController keyboardAnimationView]];
-    }
-
-    if ([flutterViewController keyboardSpringAnimation] == nil) {
-      if (flutterViewController.get().keyboardAnimationView.layer.presentationLayer) {
-        flutterViewController.get()->_viewportMetrics.physical_view_inset_bottom =
-            flutterViewController.get()
-                .keyboardAnimationView.layer.presentationLayer.frame.origin.y;
-        [flutterViewController updateViewportMetricsIfNeeded];
-      }
-    } else {
-      fml::TimeDelta timeElapsed =
-          keyboardAnimationTargetTime - flutterViewController.get().keyboardAnimationStartTime;
-      flutterViewController.get()->_viewportMetrics.physical_view_inset_bottom =
-          [[flutterViewController keyboardSpringAnimation] curveFunction:timeElapsed.ToSecondsF()];
-      [flutterViewController updateViewportMetricsIfNeeded];
-    }
-  };
-  [self setUpKeyboardAnimationVsyncClient:keyboardAnimationCallback];
+  __weak FlutterViewController* weakSelf = self;
+  [self setUpKeyboardAnimationVsyncClient:^(fml::TimePoint targetTime) {
+    [weakSelf handleKeyboardAnimationCallbackWithTargetTime:targetTime];
+  }];
   VSyncClient* currentVsyncClient = _keyboardAnimationVSyncClient;
 
   [UIView animateWithDuration:duration
       animations:^{
+        FlutterViewController* strongSelf = weakSelf;
+        if (!strongSelf) {
+          return;
+        }
+
         // Set end value.
-        [self keyboardAnimationView].frame = CGRectMake(0, self.targetViewInsetBottom, 0, 0);
+        strongSelf.keyboardAnimationView.frame = CGRectMake(0, self.targetViewInsetBottom, 0, 0);
 
         // Setup keyboard animation interpolation.
         CAAnimation* keyboardAnimation =
-            [[self keyboardAnimationView].layer animationForKey:@"position"];
-        [self setUpKeyboardSpringAnimationIfNeeded:keyboardAnimation];
+            [strongSelf.keyboardAnimationView.layer animationForKey:@"position"];
+        [strongSelf setUpKeyboardSpringAnimationIfNeeded:keyboardAnimation];
       }
       completion:^(BOOL finished) {
         if (_keyboardAnimationVSyncClient == currentVsyncClient) {
+          FlutterViewController* strongSelf = weakSelf;
+          if (!strongSelf) {
+            return;
+          }
+
           // Indicates the vsync client captured by this block is the original one, which also
           // indicates the animation has not been interrupted from its beginning. Moreover,
           // indicates the animation is over and there is no more to execute.
-          [self invalidateKeyboardAnimationVSyncClient];
-          [self removeKeyboardAnimationView];
-          [self ensureViewportMetricsIsCorrect];
+          [strongSelf invalidateKeyboardAnimationVSyncClient];
+          [strongSelf removeKeyboardAnimationView];
+          [strongSelf ensureViewportMetricsIsCorrect];
         }
       }];
 }
@@ -1793,19 +1766,54 @@ - (void)startKeyBoardAnimation:(NSTimeInterval)duration {
 - (void)setUpKeyboardSpringAnimationIfNeeded:(CAAnimation*)keyboardAnimation {
   // If keyboard animation is null or not a spring animation, fallback to DisplayLink tracking.
   if (keyboardAnimation == nil || ![keyboardAnimation isKindOfClass:[CASpringAnimation class]]) {
-    _keyboardSpringAnimation.reset();
+    _keyboardSpringAnimation = nil;
     return;
   }
 
   // Setup keyboard spring animation details for spring curve animation calculation.
   CASpringAnimation* keyboardCASpringAnimation = (CASpringAnimation*)keyboardAnimation;
-  _keyboardSpringAnimation.reset([[SpringAnimation alloc]
-      initWithStiffness:keyboardCASpringAnimation.stiffness
-                damping:keyboardCASpringAnimation.damping
-                   mass:keyboardCASpringAnimation.mass
-        initialVelocity:keyboardCASpringAnimation.initialVelocity
-              fromValue:self.originalViewInsetBottom
-                toValue:self.targetViewInsetBottom]);
+  _keyboardSpringAnimation =
+      [[SpringAnimation alloc] initWithStiffness:keyboardCASpringAnimation.stiffness
+                                         damping:keyboardCASpringAnimation.damping
+                                            mass:keyboardCASpringAnimation.mass
+                                 initialVelocity:keyboardCASpringAnimation.initialVelocity
+                                       fromValue:self.originalViewInsetBottom
+                                         toValue:self.targetViewInsetBottom];
+}
+
+- (void)handleKeyboardAnimationCallbackWithTargetTime:(fml::TimePoint)targetTime {
+  // If the view controller's view is not loaded, bail out.
+  if (!self.isViewLoaded) {
+    return;
+  }
+  // If the view for tracking keyboard animation is nil, means it is not
+  // created, bail out.
+  if (!self.keyboardAnimationView) {
+    return;
+  }
+  // If keyboardAnimationVSyncClient is nil, means the animation ends.
+  // And should bail out.
+  if (!self.keyboardAnimationVSyncClient) {
+    return;
+  }
+
+  if (!self.keyboardAnimationView.superview) {
+    // Ensure the keyboardAnimationView is in view hierarchy when animation running.
+    [self.view addSubview:self.keyboardAnimationView];
+  }
+
+  if (!self.keyboardSpringAnimation) {
+    if (self.keyboardAnimationView.layer.presentationLayer) {
+      self->_viewportMetrics.physical_view_inset_bottom =
+          self.keyboardAnimationView.layer.presentationLayer.frame.origin.y;
+      [self updateViewportMetricsIfNeeded];
+    }
+  } else {
+    fml::TimeDelta timeElapsed = targetTime - self.keyboardAnimationStartTime;
+    self->_viewportMetrics.physical_view_inset_bottom =
+        [self.keyboardSpringAnimation curveFunction:timeElapsed.ToSecondsF()];
+    [self updateViewportMetricsIfNeeded];
+  }
 }
 
 - (void)setUpKeyboardAnimationVsyncClient:
@@ -1817,17 +1825,16 @@ - (void)setUpKeyboardAnimationVsyncClient:
            @"_keyboardAnimationVSyncClient must be nil when setting up.");
 
   // Make sure the new viewport metrics get sent after the begin frame event has processed.
-  fml::scoped_nsprotocol<FlutterKeyboardAnimationCallback> animationCallback(
-      [keyboardAnimationCallback copy]);
+  FlutterKeyboardAnimationCallback animationCallback = [keyboardAnimationCallback copy];
   auto uiCallback = [animationCallback](std::unique_ptr<flutter::FrameTimingsRecorder> recorder) {
     fml::TimeDelta frameInterval = recorder->GetVsyncTargetTime() - recorder->GetVsyncStartTime();
-    fml::TimePoint keyboardAnimationTargetTime = recorder->GetVsyncTargetTime() + frameInterval;
+    fml::TimePoint targetTime = recorder->GetVsyncTargetTime() + frameInterval;
     dispatch_async(dispatch_get_main_queue(), ^(void) {
-      animationCallback.get()(keyboardAnimationTargetTime);
+      animationCallback(targetTime);
     });
   };
 
-  _keyboardAnimationVSyncClient = [[VSyncClient alloc] initWithTaskRunner:[_engine uiTaskRunner]
+  _keyboardAnimationVSyncClient = [[VSyncClient alloc] initWithTaskRunner:[self.engine uiTaskRunner]
                                                                  callback:uiCallback];
   _keyboardAnimationVSyncClient.allowPauseAfterVsync = NO;
   [_keyboardAnimationVSyncClient await];
@@ -1835,13 +1842,12 @@ - (void)setUpKeyboardAnimationVsyncClient:
 
 - (void)invalidateKeyboardAnimationVSyncClient {
   [_keyboardAnimationVSyncClient invalidate];
-  [_keyboardAnimationVSyncClient release];
   _keyboardAnimationVSyncClient = nil;
 }
 
 - (void)removeKeyboardAnimationView {
-  if ([self keyboardAnimationView].superview != nil) {
-    [[self keyboardAnimationView] removeFromSuperview];
+  if (self.keyboardAnimationView.superview != nil) {
+    [self.keyboardAnimationView removeFromSuperview];
   }
 }
 
@@ -1864,7 +1870,8 @@ - (void)handlePressEvent:(FlutterUIPressProxy*)press
 }
 
 - (void)sendDeepLinkToFramework:(NSURL*)url completionHandler:(void (^)(BOOL success))completion {
-  [_engine.get()
+  __weak FlutterViewController* weakSelf = self;
+  [self.engine
       waitForFirstFrame:3.0
                callback:^(BOOL didTimeout) {
                  if (didTimeout) {
@@ -1872,7 +1879,7 @@ - (void)sendDeepLinkToFramework:(NSURL*)url completionHandler:(void (^)(BOOL suc
                    completion(NO);
                  } else {
                    // invove the method and get the result
-                   [[_engine.get() navigationChannel]
+                   [weakSelf.engine.navigationChannel
                        invokeMethod:@"pushRouteInformation"
                           arguments:@{
                             @"location" : url.absoluteString ?: [NSNull null],
@@ -1899,20 +1906,39 @@ - (void)sendDeepLinkToFramework:(NSURL*)url completionHandler:(void (^)(BOOL suc
 // the wild, however, so I suspect that the API is built for a tvOS remote or
 // something, and perhaps only one ever appears in the set on iOS from a
 // keyboard.
+//
+// We define separate superPresses* overrides to avoid implicitly capturing self in the blocks
+// passed to the presses* methods below.
+
+- (void)superPressesBegan:(NSSet<UIPress*>*)presses withEvent:(UIPressesEvent*)event {
+  [super pressesBegan:presses withEvent:event];
+}
+
+- (void)superPressesChanged:(NSSet<UIPress*>*)presses withEvent:(UIPressesEvent*)event {
+  [super pressesChanged:presses withEvent:event];
+}
+
+- (void)superPressesEnded:(NSSet<UIPress*>*)presses withEvent:(UIPressesEvent*)event {
+  [super pressesEnded:presses withEvent:event];
+}
+
+- (void)superPressesCancelled:(NSSet<UIPress*>*)presses withEvent:(UIPressesEvent*)event {
+  [super pressesCancelled:presses withEvent:event];
+}
 
 // If you substantially change these presses overrides, consider also changing
 // the similar ones in FlutterTextInputPlugin. They need to be overridden in
 // both places to capture keys both inside and outside of a text field, but have
-// slightly different implmentations.
+// slightly different implementations.
 
 - (void)pressesBegan:(NSSet<UIPress*>*)presses
            withEvent:(UIPressesEvent*)event API_AVAILABLE(ios(9.0)) {
   if (@available(iOS 13.4, *)) {
+    __weak FlutterViewController* weakSelf = self;
     for (UIPress* press in presses) {
-      [self handlePressEvent:[[[FlutterUIPressProxy alloc] initWithPress:press
-                                                               withEvent:event] autorelease]
+      [self handlePressEvent:[[FlutterUIPressProxy alloc] initWithPress:press withEvent:event]
                   nextAction:^() {
-                    [super pressesBegan:[NSSet setWithObject:press] withEvent:event];
+                    [weakSelf superPressesBegan:[NSSet setWithObject:press] withEvent:event];
                   }];
     }
   } else {
@@ -1923,11 +1949,11 @@ - (void)pressesBegan:(NSSet<UIPress*>*)presses
 - (void)pressesChanged:(NSSet<UIPress*>*)presses
              withEvent:(UIPressesEvent*)event API_AVAILABLE(ios(9.0)) {
   if (@available(iOS 13.4, *)) {
+    __weak FlutterViewController* weakSelf = self;
     for (UIPress* press in presses) {
-      [self handlePressEvent:[[[FlutterUIPressProxy alloc] initWithPress:press
-                                                               withEvent:event] autorelease]
+      [self handlePressEvent:[[FlutterUIPressProxy alloc] initWithPress:press withEvent:event]
                   nextAction:^() {
-                    [super pressesChanged:[NSSet setWithObject:press] withEvent:event];
+                    [weakSelf superPressesChanged:[NSSet setWithObject:press] withEvent:event];
                   }];
     }
   } else {
@@ -1938,11 +1964,11 @@ - (void)pressesChanged:(NSSet<UIPress*>*)presses
 - (void)pressesEnded:(NSSet<UIPress*>*)presses
            withEvent:(UIPressesEvent*)event API_AVAILABLE(ios(9.0)) {
   if (@available(iOS 13.4, *)) {
+    __weak FlutterViewController* weakSelf = self;
     for (UIPress* press in presses) {
-      [self handlePressEvent:[[[FlutterUIPressProxy alloc] initWithPress:press
-                                                               withEvent:event] autorelease]
+      [self handlePressEvent:[[FlutterUIPressProxy alloc] initWithPress:press withEvent:event]
                   nextAction:^() {
-                    [super pressesEnded:[NSSet setWithObject:press] withEvent:event];
+                    [weakSelf superPressesEnded:[NSSet setWithObject:press] withEvent:event];
                   }];
     }
   } else {
@@ -1953,11 +1979,11 @@ - (void)pressesEnded:(NSSet<UIPress*>*)presses
 - (void)pressesCancelled:(NSSet<UIPress*>*)presses
                withEvent:(UIPressesEvent*)event API_AVAILABLE(ios(9.0)) {
   if (@available(iOS 13.4, *)) {
+    __weak FlutterViewController* weakSelf = self;
     for (UIPress* press in presses) {
-      [self handlePressEvent:[[[FlutterUIPressProxy alloc] initWithPress:press
-                                                               withEvent:event] autorelease]
+      [self handlePressEvent:[[FlutterUIPressProxy alloc] initWithPress:press withEvent:event]
                   nextAction:^() {
-                    [super pressesCancelled:[NSSet setWithObject:press] withEvent:event];
+                    [weakSelf superPressesCancelled:[NSSet setWithObject:press] withEvent:event];
                   }];
     }
   } else {
@@ -1969,15 +1995,14 @@ - (void)pressesCancelled:(NSSet<UIPress*>*)presses
 
 - (void)onOrientationPreferencesUpdated:(NSNotification*)notification {
   // Notifications may not be on the iOS UI thread
+  __weak FlutterViewController* weakSelf = self;
   dispatch_async(dispatch_get_main_queue(), ^{
     NSDictionary* info = notification.userInfo;
-
     NSNumber* update = info[@(flutter::kOrientationUpdateNotificationKey)];
-
     if (update == nil) {
       return;
     }
-    [self performOrientationUpdate:update.unsignedIntegerValue];
+    [weakSelf performOrientationUpdate:update.unsignedIntegerValue];
   });
 }
 
@@ -1985,8 +2010,8 @@ - (void)requestGeometryUpdateForWindowScenes:(NSSet<UIScene*>*)windowScenes
     API_AVAILABLE(ios(16.0)) {
   for (UIScene* windowScene in windowScenes) {
     FML_DCHECK([windowScene isKindOfClass:[UIWindowScene class]]);
-    UIWindowSceneGeometryPreferencesIOS* preference = [[[UIWindowSceneGeometryPreferencesIOS alloc]
-        initWithInterfaceOrientations:_orientationPreferences] autorelease];
+    UIWindowSceneGeometryPreferencesIOS* preference = [[UIWindowSceneGeometryPreferencesIOS alloc]
+        initWithInterfaceOrientations:self.orientationPreferences];
     [(UIWindowScene*)windowScene
         requestGeometryUpdateWithPreferences:preference
                                 errorHandler:^(NSError* error) {
@@ -1998,8 +2023,8 @@ - (void)requestGeometryUpdateForWindowScenes:(NSSet<UIScene*>*)windowScenes
 }
 
 - (void)performOrientationUpdate:(UIInterfaceOrientationMask)new_preferences {
-  if (new_preferences != _orientationPreferences) {
-    _orientationPreferences = new_preferences;
+  if (new_preferences != self.orientationPreferences) {
+    self.orientationPreferences = new_preferences;
 
     if (@available(iOS 16.0, *)) {
       NSSet<UIScene*>* scenes =
@@ -2018,7 +2043,7 @@ - (void)performOrientationUpdate:(UIInterfaceOrientationMask)new_preferences {
     } else {
       UIInterfaceOrientationMask currentInterfaceOrientation = 0;
       if (@available(iOS 13.0, *)) {
-        UIWindowScene* windowScene = [self flutterWindowSceneIfViewLoaded];
+        UIWindowScene* windowScene = self.flutterWindowSceneIfViewLoaded;
         if (!windowScene) {
           FML_LOG(WARNING)
               << "Accessing the interface orientation when the window scene is unavailable.";
@@ -2034,22 +2059,22 @@ - (void)performOrientationUpdate:(UIInterfaceOrientationMask)new_preferences {
         currentInterfaceOrientation = 1 << [[UIApplication sharedApplication] statusBarOrientation];
 #endif
       }
-      if (!(_orientationPreferences & currentInterfaceOrientation)) {
+      if (!(self.orientationPreferences & currentInterfaceOrientation)) {
         [UIViewController attemptRotationToDeviceOrientation];
         // Force orientation switch if the current orientation is not allowed
-        if (_orientationPreferences & UIInterfaceOrientationMaskPortrait) {
+        if (self.orientationPreferences & UIInterfaceOrientationMaskPortrait) {
           // This is no official API but more like a workaround / hack (using
           // key-value coding on a read-only property). This might break in
           // the future, but currently it´s the only way to force an orientation change
           [[UIDevice currentDevice] setValue:@(UIInterfaceOrientationPortrait)
                                       forKey:@"orientation"];
-        } else if (_orientationPreferences & UIInterfaceOrientationMaskPortraitUpsideDown) {
+        } else if (self.orientationPreferences & UIInterfaceOrientationMaskPortraitUpsideDown) {
           [[UIDevice currentDevice] setValue:@(UIInterfaceOrientationPortraitUpsideDown)
                                       forKey:@"orientation"];
-        } else if (_orientationPreferences & UIInterfaceOrientationMaskLandscapeLeft) {
+        } else if (self.orientationPreferences & UIInterfaceOrientationMaskLandscapeLeft) {
           [[UIDevice currentDevice] setValue:@(UIInterfaceOrientationLandscapeLeft)
                                       forKey:@"orientation"];
-        } else if (_orientationPreferences & UIInterfaceOrientationMaskLandscapeRight) {
+        } else if (self.orientationPreferences & UIInterfaceOrientationMaskLandscapeRight) {
           [[UIDevice currentDevice] setValue:@(UIInterfaceOrientationLandscapeRight)
                                       forKey:@"orientation"];
         }
@@ -2082,17 +2107,17 @@ - (BOOL)shouldAutorotate {
 }
 
 - (NSUInteger)supportedInterfaceOrientations {
-  return _orientationPreferences;
+  return self.orientationPreferences;
 }
 
 #pragma mark - Accessibility
 
 - (void)onAccessibilityStatusChanged:(NSNotification*)notification {
-  if (!_engine) {
+  if (!self.engine) {
     return;
   }
-  auto platformView = [_engine.get() platformView];
-  int32_t flags = [self accessibilityFlags];
+  fml::WeakPtr<flutter::PlatformView> platformView = self.engine.platformView;
+  int32_t flags = self.accessibilityFlags;
 #if TARGET_OS_SIMULATOR
   // There doesn't appear to be any way to determine whether the accessibility
   // inspector is enabled on the simulator. We conservatively always turn on the
@@ -2132,7 +2157,7 @@ - (int32_t)accessibilityFlags {
 }
 
 - (BOOL)accessibilityPerformEscape {
-  FlutterMethodChannel* navigationChannel = [_engine.get() navigationChannel];
+  FlutterMethodChannel* navigationChannel = self.engine.navigationChannel;
   if (navigationChannel) {
     [self popRoute];
     return YES;
@@ -2156,13 +2181,13 @@ - (void)traitCollectionDidChange:(UITraitCollection*)previousTraitCollection {
 }
 
 - (void)onUserSettingsChanged:(NSNotification*)notification {
-  [[_engine.get() settingsChannel] sendMessage:@{
-    @"textScaleFactor" : @([self textScaleFactor]),
-    @"alwaysUse24HourFormat" : @([FlutterHourFormat isAlwaysUse24HourFormat]),
-    @"platformBrightness" : [self brightnessMode],
-    @"platformContrast" : [self contrastMode],
-    @"nativeSpellCheckServiceDefined" : @true,
-    @"supportsShowingSystemContextMenu" : @([self supportsShowingSystemContextMenu])
+  [self.engine.settingsChannel sendMessage:@{
+    @"textScaleFactor" : @(self.textScaleFactor),
+    @"alwaysUse24HourFormat" : @(FlutterHourFormat.isAlwaysUse24HourFormat),
+    @"platformBrightness" : self.brightnessMode,
+    @"platformContrast" : self.contrastMode,
+    @"nativeSpellCheckServiceDefined" : @YES,
+    @"supportsShowingSystemContextMenu" : @(self.supportsShowingSystemContextMenu)
   }];
 }
 
@@ -2269,25 +2294,28 @@ - (NSString*)contrastMode {
 #pragma mark - Status bar style
 
 - (UIStatusBarStyle)preferredStatusBarStyle {
-  return _statusBarStyle;
+  return self.statusBarStyle;
 }
 
 - (void)onPreferredStatusBarStyleUpdated:(NSNotification*)notification {
   // Notifications may not be on the iOS UI thread
+  __weak FlutterViewController* weakSelf = self;
   dispatch_async(dispatch_get_main_queue(), ^{
-    NSDictionary* info = notification.userInfo;
+    FlutterViewController* strongSelf = weakSelf;
+    if (!strongSelf) {
+      return;
+    }
 
+    NSDictionary* info = notification.userInfo;
     NSNumber* update = info[@(flutter::kOverlayStyleUpdateNotificationKey)];
-
     if (update == nil) {
       return;
     }
 
-    NSInteger style = update.integerValue;
-
-    if (style != _statusBarStyle) {
-      _statusBarStyle = static_cast<UIStatusBarStyle>(style);
-      [self setNeedsStatusBarAppearanceUpdate];
+    UIStatusBarStyle style = static_cast<UIStatusBarStyle>(update.integerValue);
+    if (style != strongSelf.statusBarStyle) {
+      strongSelf.statusBarStyle = style;
+      [strongSelf setNeedsStatusBarAppearanceUpdate];
     }
   });
 }
@@ -2306,28 +2334,28 @@ - (BOOL)prefersStatusBarHidden {
 #pragma mark - Platform views
 
 - (std::shared_ptr<flutter::PlatformViewsController>&)platformViewsController {
-  return [_engine.get() platformViewsController];
+  return self.engine.platformViewsController;
 }
 
 - (NSObject<FlutterBinaryMessenger>*)binaryMessenger {
-  return _engine.get().binaryMessenger;
+  return self.engine.binaryMessenger;
 }
 
 #pragma mark - FlutterBinaryMessenger
 
 - (void)sendOnChannel:(NSString*)channel message:(NSData*)message {
-  [_engine.get().binaryMessenger sendOnChannel:channel message:message];
+  [self.engine.binaryMessenger sendOnChannel:channel message:message];
 }
 
 - (void)sendOnChannel:(NSString*)channel
               message:(NSData*)message
           binaryReply:(FlutterBinaryReply)callback {
   NSAssert(channel, @"The channel must not be null");
-  [_engine.get().binaryMessenger sendOnChannel:channel message:message binaryReply:callback];
+  [self.engine.binaryMessenger sendOnChannel:channel message:message binaryReply:callback];
 }
 
 - (NSObject<FlutterTaskQueue>*)makeBackgroundTaskQueue {
-  return [_engine.get().binaryMessenger makeBackgroundTaskQueue];
+  return [self.engine.binaryMessenger makeBackgroundTaskQueue];
 }
 
 - (FlutterBinaryMessengerConnection)setMessageHandlerOnChannel:(NSString*)channel
@@ -2341,27 +2369,27 @@ - (FlutterBinaryMessengerConnection)setMessageHandlerOnChannel:(NSString*)channe
           binaryMessageHandler:(FlutterBinaryMessageHandler _Nullable)handler
                      taskQueue:(NSObject<FlutterTaskQueue>* _Nullable)taskQueue {
   NSAssert(channel, @"The channel must not be null");
-  return [_engine.get().binaryMessenger setMessageHandlerOnChannel:channel
-                                              binaryMessageHandler:handler
-                                                         taskQueue:taskQueue];
+  return [self.engine.binaryMessenger setMessageHandlerOnChannel:channel
+                                            binaryMessageHandler:handler
+                                                       taskQueue:taskQueue];
 }
 
 - (void)cleanUpConnection:(FlutterBinaryMessengerConnection)connection {
-  [_engine.get().binaryMessenger cleanUpConnection:connection];
+  [self.engine.binaryMessenger cleanUpConnection:connection];
 }
 
 #pragma mark - FlutterTextureRegistry
 
 - (int64_t)registerTexture:(NSObject<FlutterTexture>*)texture {
-  return [_engine.get().textureRegistry registerTexture:texture];
+  return [self.engine.textureRegistry registerTexture:texture];
 }
 
 - (void)unregisterTexture:(int64_t)textureId {
-  [_engine.get().textureRegistry unregisterTexture:textureId];
+  [self.engine.textureRegistry unregisterTexture:textureId];
 }
 
 - (void)textureFrameAvailable:(int64_t)textureId {
-  [_engine.get().textureRegistry textureFrameAvailable:textureId];
+  [self.engine.textureRegistry textureFrameAvailable:textureId];
 }
 
 - (NSString*)lookupKeyForAsset:(NSString*)asset {
@@ -2373,7 +2401,7 @@ - (NSString*)lookupKeyForAsset:(NSString*)asset fromPackage:(NSString*)package {
 }
 
 - (id<FlutterPluginRegistry>)pluginRegistry {
-  return _engine;
+  return self.engine;
 }
 
 + (BOOL)isUIAccessibilityIsVoiceOverRunning {
@@ -2383,25 +2411,26 @@ + (BOOL)isUIAccessibilityIsVoiceOverRunning {
 #pragma mark - FlutterPluginRegistry
 
 - (NSObject<FlutterPluginRegistrar>*)registrarForPlugin:(NSString*)pluginKey {
-  return [_engine.get() registrarForPlugin:pluginKey];
+  return [self.engine registrarForPlugin:pluginKey];
 }
 
 - (BOOL)hasPlugin:(NSString*)pluginKey {
-  return [_engine.get() hasPlugin:pluginKey];
+  return [self.engine hasPlugin:pluginKey];
 }
 
 - (NSObject*)valuePublishedByPlugin:(NSString*)pluginKey {
-  return [_engine.get() valuePublishedByPlugin:pluginKey];
+  return [self.engine valuePublishedByPlugin:pluginKey];
 }
 
 - (void)presentViewController:(UIViewController*)viewControllerToPresent
                      animated:(BOOL)flag
                    completion:(void (^)(void))completion {
   self.isPresentingViewControllerAnimating = YES;
+  __weak FlutterViewController* weakSelf = self;
   [super presentViewController:viewControllerToPresent
                       animated:flag
                     completion:^{
-                      self.isPresentingViewControllerAnimating = NO;
+                      weakSelf.isPresentingViewControllerAnimating = NO;
                       if (completion) {
                         completion();
                       }
@@ -2415,7 +2444,7 @@ - (BOOL)isPresentingViewController {
 - (flutter::PointerData)updateMousePointerDataFrom:(UIGestureRecognizer*)gestureRecognizer
     API_AVAILABLE(ios(13.4)) {
   CGPoint location = [gestureRecognizer locationInView:self.view];
-  CGFloat scale = [self flutterScreenIfViewLoaded].scale;
+  CGFloat scale = self.flutterScreenIfViewLoaded.scale;
   _mouseState.location = {location.x * scale, location.y * scale};
   flutter::PointerData pointer_data;
   pointer_data.Clear();
@@ -2442,13 +2471,13 @@ - (BOOL)gestureRecognizer:(UIGestureRecognizer*)gestureRecognizer
     pointer_data.signal_kind = flutter::PointerData::SignalKind::kScrollInertiaCancel;
     pointer_data.view_id = self.viewIdentifier;
 
-    if (event.timestamp < _scrollInertiaEventAppKitDeadline) {
+    if (event.timestamp < self.scrollInertiaEventAppKitDeadline) {
       // Only send the event if it occured before the expected natural end of gesture momentum.
       // If received after the deadline, it's not likely the event is from a user-initiated cancel.
       auto packet = std::make_unique<flutter::PointerDataPacket>(1);
       packet->SetPointerData(/*i=*/0, pointer_data);
-      [_engine.get() dispatchPointerDataPacket:std::move(packet)];
-      _scrollInertiaEventAppKitDeadline = 0;
+      [self.engine dispatchPointerDataPacket:std::move(packet)];
+      self.scrollInertiaEventAppKitDeadline = 0;
     }
   }
   // This method is also called for UITouches, should return YES to process all touches.
@@ -2490,7 +2519,7 @@ - (void)hoverEvent:(UIHoverGestureRecognizer*)recognizer API_AVAILABLE(ios(13.4)
     isRunningOnMac = [NSProcessInfo processInfo].iOSAppOnMac;
   }
   if (!isRunningOnMac && CGPointEqualToPoint(oldLocation, _mouseState.location) &&
-      time > _scrollInertiaEventStartline) {
+      time > self.scrollInertiaEventStartline) {
     // iPadOS reports trackpad movements events with high (sub-pixel) precision. When an event
     // is received with the same position as the previous one, it can only be from a finger
     // making or breaking contact with the trackpad surface.
@@ -2502,18 +2531,18 @@ - (void)hoverEvent:(UIHoverGestureRecognizer*)recognizer API_AVAILABLE(ios(13.4)
     inertia_cancel.signal_kind = flutter::PointerData::SignalKind::kScrollInertiaCancel;
     inertia_cancel.view_id = self.viewIdentifier;
     packet->SetPointerData(/*i=*/1, inertia_cancel);
-    [_engine.get() dispatchPointerDataPacket:std::move(packet)];
-    _scrollInertiaEventStartline = DBL_MAX;
+    [self.engine dispatchPointerDataPacket:std::move(packet)];
+    self.scrollInertiaEventStartline = DBL_MAX;
   } else {
     auto packet = std::make_unique<flutter::PointerDataPacket>(1);
     packet->SetPointerData(/*i=*/0, pointer_data);
-    [_engine.get() dispatchPointerDataPacket:std::move(packet)];
+    [self.engine dispatchPointerDataPacket:std::move(packet)];
   }
 }
 
 - (void)discreteScrollEvent:(UIPanGestureRecognizer*)recognizer API_AVAILABLE(ios(13.4)) {
   CGPoint translation = [recognizer translationInView:self.view];
-  const CGFloat scale = [self flutterScreenIfViewLoaded].scale;
+  const CGFloat scale = self.flutterScreenIfViewLoaded.scale;
 
   translation.x *= scale;
   translation.y *= scale;
@@ -2538,12 +2567,12 @@ - (void)discreteScrollEvent:(UIPanGestureRecognizer*)recognizer API_AVAILABLE(io
 
   auto packet = std::make_unique<flutter::PointerDataPacket>(1);
   packet->SetPointerData(/*i=*/0, pointer_data);
-  [_engine.get() dispatchPointerDataPacket:std::move(packet)];
+  [self.engine dispatchPointerDataPacket:std::move(packet)];
 }
 
 - (void)continuousScrollEvent:(UIPanGestureRecognizer*)recognizer API_AVAILABLE(ios(13.4)) {
   CGPoint translation = [recognizer translationInView:self.view];
-  const CGFloat scale = [self flutterScreenIfViewLoaded].scale;
+  const CGFloat scale = self.flutterScreenIfViewLoaded.scale;
 
   flutter::PointerData pointer_data = [self updateMousePointerDataFrom:recognizer];
   pointer_data.device = reinterpret_cast<int64_t>(recognizer);
@@ -2563,7 +2592,7 @@ - (void)continuousScrollEvent:(UIPanGestureRecognizer*)recognizer API_AVAILABLE(
       break;
     case UIGestureRecognizerStateEnded:
     case UIGestureRecognizerStateCancelled:
-      _scrollInertiaEventStartline =
+      self.scrollInertiaEventStartline =
           [[NSProcessInfo processInfo] systemUptime] +
           0.1;  // Time to lift fingers off trackpad (experimentally determined)
       // When running an iOS app on an Apple Silicon Mac, AppKit will send an event
@@ -2574,7 +2603,7 @@ - (void)continuousScrollEvent:(UIPanGestureRecognizer*)recognizer API_AVAILABLE(
       // The following (curve-fitted) calculation provides a cutoff point after which any
       // UIEventTypeScroll event will likely be from the system instead of the user.
       // See https://github.com/flutter/engine/pull/34929.
-      _scrollInertiaEventAppKitDeadline =
+      self.scrollInertiaEventAppKitDeadline =
           [[NSProcessInfo processInfo] systemUptime] +
           (0.1821 * log(fmax([recognizer velocityInView:self.view].x,
                              [recognizer velocityInView:self.view].y))) -
@@ -2583,14 +2612,14 @@ - (void)continuousScrollEvent:(UIPanGestureRecognizer*)recognizer API_AVAILABLE(
       break;
     default:
       // continuousScrollEvent: should only ever be triggered with the above phases
-      NSAssert(false, @"Trackpad pan event occured with unexpected phase 0x%lx",
+      NSAssert(NO, @"Trackpad pan event occured with unexpected phase 0x%lx",
                (long)recognizer.state);
       break;
   }
 
   auto packet = std::make_unique<flutter::PointerDataPacket>(1);
   packet->SetPointerData(/*i=*/0, pointer_data);
-  [_engine.get() dispatchPointerDataPacket:std::move(packet)];
+  [self.engine dispatchPointerDataPacket:std::move(packet)];
 }
 
 - (void)pinchEvent:(UIPinchGestureRecognizer*)recognizer API_AVAILABLE(ios(13.4)) {
@@ -2613,20 +2642,20 @@ - (void)pinchEvent:(UIPinchGestureRecognizer*)recognizer API_AVAILABLE(ios(13.4)
       break;
     default:
       // pinchEvent: should only ever be triggered with the above phases
-      NSAssert(false, @"Trackpad pinch event occured with unexpected phase 0x%lx",
+      NSAssert(NO, @"Trackpad pinch event occured with unexpected phase 0x%lx",
                (long)recognizer.state);
       break;
   }
 
   auto packet = std::make_unique<flutter::PointerDataPacket>(1);
   packet->SetPointerData(/*i=*/0, pointer_data);
-  [_engine.get() dispatchPointerDataPacket:std::move(packet)];
+  [self.engine dispatchPointerDataPacket:std::move(packet)];
 }
 
 #pragma mark - State Restoration
 
 - (void)encodeRestorableStateWithCoder:(NSCoder*)coder {
-  NSData* restorationData = [[_engine.get() restorationPlugin] restorationData];
+  NSData* restorationData = [self.engine.restorationPlugin restorationData];
   [coder encodeBytes:(const unsigned char*)restorationData.bytes
               length:restorationData.length
               forKey:kFlutterRestorationStateAppData];
@@ -2638,11 +2667,11 @@ - (void)decodeRestorableStateWithCoder:(NSCoder*)coder {
   const unsigned char* restorationBytes = [coder decodeBytesForKey:kFlutterRestorationStateAppData
                                                     returnedLength:&restorationDataLength];
   NSData* restorationData = [NSData dataWithBytes:restorationBytes length:restorationDataLength];
-  [[_engine.get() restorationPlugin] setRestorationData:restorationData];
+  [self.engine.restorationPlugin setRestorationData:restorationData];
 }
 
 - (FlutterRestorationPlugin*)restorationPlugin {
-  return [_engine.get() restorationPlugin];
+  return self.engine.restorationPlugin;
 }
 
 @end
diff --git a/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h b/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h
index c41533ff9c041..db9fc37bfd75f 100644
--- a/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h
+++ b/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h
@@ -46,7 +46,7 @@ typedef void (^FlutterKeyboardAnimationCallback)(fml::TimePoint);
 @property(class, nonatomic, readonly) BOOL accessibilityIsOnOffSwitchLabelsEnabled;
 @property(nonatomic, readonly) BOOL isPresentingViewController;
 @property(nonatomic, readonly) BOOL isVoiceOverRunning;
-@property(nonatomic, retain) FlutterKeyboardManager* keyboardManager;
+@property(nonatomic, strong) FlutterKeyboardManager* keyboardManager;
 
 /**
  * @brief Whether the status bar is preferred hidden.