diff --git a/apps/mobile/src/features/home/HomeScreen.tsx b/apps/mobile/src/features/home/HomeScreen.tsx
index 2ae486cb64ab..e8ab5a492958 100644
--- a/apps/mobile/src/features/home/HomeScreen.tsx
+++ b/apps/mobile/src/features/home/HomeScreen.tsx
@@ -1140,6 +1140,22 @@ export function HomeScreen(props: HomeScreenProps) {
       listEmpty
     );
 
+  // T3-CUSTOM(expbkt3): BEGIN — the experimental phase sidebar replaces the
+  // whole list. This MUST sit above the threadListV2Enabled return below:
+  // that flag defaults to true, so anything after it is unreachable.
+  if (phaseSidebarEnabled) {
+    return (
+      <View className="flex-1 bg-screen">
+        <PhaseSidebarPane
+          onSelectThread={props.onSelectThread}
+          selectedThreadKey={null}
+          viewerEnvironmentId={props.selectedEnvironmentId}
+        />
+      </View>
+    );
+  }
+  // T3-CUSTOM(expbkt3): END
+
   if (threadListV2Enabled) {
     return (
       <View className="flex-1 bg-screen">
@@ -1186,23 +1202,6 @@ export function HomeScreen(props: HomeScreenProps) {
     );
   }
 
-  // T3-CUSTOM(expbkt3): BEGIN — the experimental phase sidebar replaces this
-  // list entirely when enabled. It has to be wired here as well as in
-  // ThreadNavigationSidebar: that pane only renders in split view, so on a
-  // phone (compact layout) this screen IS the thread list.
-  if (phaseSidebarEnabled) {
-    return (
-      <View className="flex-1 bg-screen">
-        <PhaseSidebarPane
-          onSelectThread={props.onSelectThread}
-          selectedThreadKey={null}
-          viewerEnvironmentId={props.selectedEnvironmentId}
-        />
-      </View>
-    );
-  }
-  // T3-CUSTOM(expbkt3): END
-
   return (
     <View className="flex-1 bg-screen">
       {/* Sticky headers are deliberately not wired up: LegendList's JS sticky
diff --git a/apps/mobile/src/features/threads/ThreadNavigationSidebar.tsx b/apps/mobile/src/features/threads/ThreadNavigationSidebar.tsx
index 5308019ebc0e..7d2a242d0fe7 100644
--- a/apps/mobile/src/features/threads/ThreadNavigationSidebar.tsx
+++ b/apps/mobile/src/features/threads/ThreadNavigationSidebar.tsx
@@ -1264,6 +1264,22 @@ function ThreadNavigationSidebarPane(
     );
   }
 
+  // T3-CUSTOM(expbkt3): BEGIN — the experimental sidebar replaces this render
+  // path too. The nativeChrome branch above has its own copy; both paths render
+  // a thread list, so gating only one leaves the flag half-wired.
+  if (phaseSidebarEnabled) {
+    return (
+      <View className="flex-1" style={{ width: props.width }}>
+        <PhaseSidebarPane
+          onSelectThread={props.onSelectThread}
+          selectedThreadKey={props.selectedThreadKey}
+          viewerEnvironmentId={phaseSidebarViewerEnvironmentId}
+        />
+      </View>
+    );
+  }
+  // T3-CUSTOM(expbkt3): END
+
   return (
     <View
       testID="thread-navigation-sidebar"
diff --git a/apps/mobile/src/lib/bkBuildManifest.ts b/apps/mobile/src/lib/bkBuildManifest.ts
index 810a5d9149f8..82028de50a3c 100644
--- a/apps/mobile/src/lib/bkBuildManifest.ts
+++ b/apps/mobile/src/lib/bkBuildManifest.ts
@@ -1,29 +1,18 @@
 // T3-CUSTOM(expbkt3): The Expo-manifest half of the fork build identity.
 //
 // Split from bkBuildIdentity.ts so the version-formatting logic stays testable
-// without pulling react-native into the unit test environment. That split was
-// incomplete: `authClientMetadata` imports this module, so a module-scope
-// `expo-constants` import put expo-modules-core on the import graph of every
-// test reaching authClientMetadata, and expo-modules-core reads React Native's
-// `__DEV__` global as a side effect — which vitest does not define.
+// without pulling react-native into the unit test environment.
 //
-// So the manifest read is both function-scoped and fail-soft. Outside a real
-// Expo runtime there is no manifest to read, and "no manifest" already has a
-// defined meaning here: no SHA, so `bkAppVersion` returns the plain version.
-import { readBkGitSha } from "./bkBuildIdentity";
+// The import is static, like every other expo-constants consumer in the app.
+// An earlier version made it a fail-soft `require` to keep expo-modules-core off
+// the import graph of tests reaching `authClientMetadata` — that silently
+// swallowed the real read too, so builds reported a bare `1.0.4` with no
+// `+bk.<sha>` suffix and the version-skew check the fork depends on was blind.
+// Tests mock this module instead, which is what the rest of the suite does.
+import Constants from "expo-constants";
 
-function expoConfigExtra(): unknown {
-  try {
-    const loaded = require("expo-constants") as {
-      readonly default?: { readonly expoConfig?: { readonly extra?: unknown } };
-      readonly expoConfig?: { readonly extra?: unknown };
-    };
-    return (loaded.default ?? loaded).expoConfig?.extra;
-  } catch {
-    return null;
-  }
-}
+import { readBkGitSha } from "./bkBuildIdentity";
 
 export function bkBuildGitSha(): string | null {
-  return readBkGitSha(expoConfigExtra());
+  return readBkGitSha(Constants.expoConfig?.extra);
 }
diff --git a/apps/mobile/src/lib/connection.test.ts b/apps/mobile/src/lib/connection.test.ts
index a76db40a49f7..36ec8a7f4976 100644
--- a/apps/mobile/src/lib/connection.test.ts
+++ b/apps/mobile/src/lib/connection.test.ts
@@ -1,4 +1,9 @@
 import { afterEach, describe, expect, it, vi } from "vite-plus/test";
+
+// T3-CUSTOM(expbkt3): authClientMetadata reads the Expo manifest for the fork
+// build SHA, which pulls in expo-modules-core; that reads React Native's
+// `__DEV__` global at import time and vitest does not define it.
+vi.mock("expo-constants", () => ({ default: { expoConfig: null } }));
 import { EnvironmentId } from "@t3tools/contracts";
 
 import {