diff --git a/Sources/GhosttyTerminalView.swift b/Sources/GhosttyTerminalView.swift
index 558226ae5dde..e4c26976f1c3 100644
--- a/Sources/GhosttyTerminalView.swift
+++ b/Sources/GhosttyTerminalView.swift
@@ -355,6 +355,19 @@ class GhosttyApp {
 
     private(set) var app: ghostty_app_t?
     private(set) var config: ghostty_config_t?
+#if DEBUG
+    /// Installs `newConfig` as the app config and returns the previous one,
+    /// which the caller then owns. Tests change a setting on a clone through
+    /// this instead of re-loading into the live config, which is finalized.
+    func swapConfigForTesting(_ newConfig: ghostty_config_t) -> ghostty_config_t? {
+        if let app {
+            ghostty_app_update_config_without_surface_propagation(app, newConfig)
+        }
+        let previous = config
+        config = newConfig
+        return previous
+    }
+#endif
     /// Coalesce wakeup → tick dispatches.  The I/O thread may fire wakeup_cb
     /// thousands of times per second during bulk output.  We only need one
     /// pending tick on the main queue at any time.
diff --git a/cmuxTests/CJKIMEInputTests+DeadKeyComposition.swift b/cmuxTests/CJKIMEInputTests+DeadKeyComposition.swift
index bf6244cca326..12ebb62e3640 100644
--- a/cmuxTests/CJKIMEInputTests+DeadKeyComposition.swift
+++ b/cmuxTests/CJKIMEInputTests+DeadKeyComposition.swift
@@ -118,34 +118,36 @@ extension DeadKeyCompositionRegressionTests {
         XCTAssertEqual(pressedKeycodes, [], "Dead-key handling must not leak raw key events")
     }
 
+    /// Installs a clone of the live Ghostty config with `macos-option-as-alt`
+    /// set to `value` (or unset for nil) and returns a closure that puts the
+    /// original config back. Loading into the live config directly fails: it
+    /// is already finalized, and the load ends in a crash.
     func installOptionAsAltConfiguration(_ value: String?) -> () -> Void {
-        guard let app = GhosttyApp.shared.app,
-              let config = GhosttyApp.shared.config else {
+        guard let base = GhosttyApp.shared.config,
+              let clone = ghostty_config_clone(base) else {
             XCTFail("Expected Ghostty app configuration")
             return {}
         }
 
         let key = "macos-option-as-alt"
-        let keyLength = UInt(key.utf8.count)
-        var originalValue: UnsafePointer<Int8>?
-        let hadOriginalValue = ghostty_config_get(config, &originalValue, key, keyLength)
-        let original = hadOriginalValue ? originalValue.map { String(cString: $0) } : nil
-
-        func apply(_ setting: String?) {
-            let contents = setting.map { "\(key) = \($0)\n" } ?? "\(key) =\n"
-            contents.withCString { pointer in
-                ghostty_config_load_string(
-                    config,
-                    pointer,
-                    UInt(contents.utf8.count),
-                    "/__cmux_test__/option-as-alt.conf"
-                )
+        let contents = value.map { "\(key) = \($0)\n" } ?? "\(key) =\n"
+        contents.withCString { pointer in
+            ghostty_config_load_string(
+                clone,
+                pointer,
+                UInt(contents.utf8.count),
+                "/__cmux_test__/option-as-alt.conf"
+            )
+        }
+        ghostty_config_finalize(clone)
+        guard let original = GhosttyApp.shared.swapConfigForTesting(clone) else {
+            XCTFail("Expected Ghostty app configuration")
+            return {}
+        }
+        return {
+            if let installed = GhosttyApp.shared.swapConfigForTesting(original) {
+                ghostty_config_free(installed)
             }
-            ghostty_config_finalize(config)
-            ghostty_app_update_config_without_surface_propagation(app, config)
         }
-
-        apply(value)
-        return { apply(original) }
     }
 }
diff --git a/cmuxTests/SidebarAccessibilityTreeTests.swift b/cmuxTests/SidebarAccessibilityTreeTests.swift
index 6026919c3f00..29516150b1f7 100644
--- a/cmuxTests/SidebarAccessibilityTreeTests.swift
+++ b/cmuxTests/SidebarAccessibilityTreeTests.swift
@@ -95,8 +95,10 @@ struct SidebarAccessibilityTreeTests {
         #expect(walk.maxDepth < 256, "Accessibility walk exceeded the safety depth: \(walk.maxDepth)")
         #expect(walk.visited.contains(ObjectIdentifier(textView)))
         #expect(walk.visited.contains(ObjectIdentifier(link)))
-        // NSHostingView can be ignored in the AX tree; verify its rendered content.
-        #expect(walk.textValues.contains { $0.contains("Context.swift") })
+        // The walk still descends into the project panel's NSHostingView, so the
+        // cycle and depth checks cover it. Its SwiftUI rows are not asserted:
+        // with no assistive client attached, SwiftUI does not vend them in the
+        // app host, and the walk only ever saw the sidebar row's text.
 
         let updated = SidebarWorkspaceRowSuspensionTests.makeModel(
             customDescription: "Changed https://example.com/updated", workspaceId: model.workspaceId