diff --git a/electron/ipc/handlers.ts b/electron/ipc/handlers.ts
index 0f20dd56..958ef6d9 100644
--- a/electron/ipc/handlers.ts
+++ b/electron/ipc/handlers.ts
@@ -1664,6 +1664,66 @@ async function resolveMediaLinksForVideo(videoPath: string): Promise<{
 	return { resolvedVia: "none" };
 }
 
+/**
+ * Writes the diagnostic bundle a bug report needs: app/OS facts, the native
+ * helpers' raw stdout/stderr (which is where `[stop-timing]` and
+ * `encoder-selection` land — see nativeWindowsCaptureStop.ts), and the main
+ * process's own recent console output. Shared by the renderer's IPC call and
+ * the menu/tray "Save Diagnostics" entry point in main.ts, which has no
+ * renderer-side `projectState`/`logs` to offer and does not need to.
+ */
+export async function exportDiagnosticFile(payload: {
+	error: string;
+	stack?: string;
+	projectState: unknown;
+	logs: string[];
+}) {
+	const { filePath, canceled } = await dialog.showSaveDialog({
+		title: "Save Diagnostic File",
+		defaultPath: `openscreen-diagnostic-${Date.now()}.json`,
+		filters: [{ name: "JSON", extensions: ["json"] }],
+	});
+
+	if (canceled || !filePath) return { success: false, canceled: true };
+
+	const HELPER_OUTPUT_MAX_BYTES = 64 * 1024;
+	const tail = (s: string, max: number) => (s.length <= max ? s : s.slice(s.length - max));
+
+	const diagnostic = {
+		timestamp: new Date().toISOString(),
+		appVersion: app.getVersion(),
+		platform: process.platform,
+		arch: process.arch,
+		// The same fact the About box leads with, and for the same reason: it is what
+		// explains why a copy does or does not offer an update check. This file is the
+		// artifact users actually attach, so it must not be the one that omits it.
+		channel: getInstallChannel(),
+		osRelease: os.release(),
+		osVersion: os.version(),
+		totalMemoryMB: Math.round(os.totalmem() / 1024 / 1024),
+		nodeVersion: process.versions.node,
+		electronVersion: process.versions.electron,
+		chromeVersion: process.versions.chrome,
+		error: payload.error,
+		stack: payload.stack,
+		projectState: payload.projectState,
+		recentLogs: payload.logs,
+		helperOutput: {
+			windows: tail(nativeWindowsCaptureOutput, HELPER_OUTPUT_MAX_BYTES),
+			mac: tail(nativeMacCaptureOutput, HELPER_OUTPUT_MAX_BYTES),
+		},
+		mainProcessLogs: mainLogBuffer.snapshot(),
+	};
+
+	try {
+		await fs.writeFile(filePath, JSON.stringify(diagnostic, null, 2), "utf-8");
+		return { success: true, path: filePath };
+	} catch (error) {
+		console.error("Failed to write diagnostic file:", error);
+		return { success: false, error: String(error) };
+	}
+}
+
 export function registerIpcHandlers(
 	createEditorWindow: () => void,
 	createSourceSelectorWindow: () => BrowserWindow,
@@ -4092,55 +4152,8 @@ export function registerIpcHandlers(
 
 	ipcMain.handle(
 		"save-diagnostic",
-		async (
-			_,
-			payload: { error: string; stack?: string; projectState: unknown; logs: string[] },
-		) => {
-			const { filePath, canceled } = await dialog.showSaveDialog({
-				title: "Save Diagnostic File",
-				defaultPath: `openscreen-diagnostic-${Date.now()}.json`,
-				filters: [{ name: "JSON", extensions: ["json"] }],
-			});
-
-			if (canceled || !filePath) return { success: false, canceled: true };
-
-			const HELPER_OUTPUT_MAX_BYTES = 64 * 1024;
-			const tail = (s: string, max: number) => (s.length <= max ? s : s.slice(s.length - max));
-
-			const diagnostic = {
-				timestamp: new Date().toISOString(),
-				appVersion: app.getVersion(),
-				platform: process.platform,
-				arch: process.arch,
-				// The same fact the About box leads with, and for the same reason: it is what
-				// explains why a copy does or does not offer an update check. This file is the
-				// artifact users actually attach, so it must not be the one that omits it.
-				channel: getInstallChannel(),
-				osRelease: os.release(),
-				osVersion: os.version(),
-				totalMemoryMB: Math.round(os.totalmem() / 1024 / 1024),
-				nodeVersion: process.versions.node,
-				electronVersion: process.versions.electron,
-				chromeVersion: process.versions.chrome,
-				error: payload.error,
-				stack: payload.stack,
-				projectState: payload.projectState,
-				recentLogs: payload.logs,
-				helperOutput: {
-					windows: tail(nativeWindowsCaptureOutput, HELPER_OUTPUT_MAX_BYTES),
-					mac: tail(nativeMacCaptureOutput, HELPER_OUTPUT_MAX_BYTES),
-				},
-				mainProcessLogs: mainLogBuffer.snapshot(),
-			};
-
-			try {
-				await fs.writeFile(filePath, JSON.stringify(diagnostic, null, 2), "utf-8");
-				return { success: true, path: filePath };
-			} catch (error) {
-				console.error("Failed to write diagnostic file:", error);
-				return { success: false, error: String(error) };
-			}
-		},
+		async (_, payload: { error: string; stack?: string; projectState: unknown; logs: string[] }) =>
+			exportDiagnosticFile(payload),
 	);
 
 	// One instance each, not one per call. DocumentService serialises saves of a
diff --git a/electron/main.ts b/electron/main.ts
index 85eb063b..a85629bf 100644
--- a/electron/main.ts
+++ b/electron/main.ts
@@ -41,7 +41,11 @@ import {
 } from "./globalShortcut";
 import { mainT, setMainLocale } from "./i18n";
 import { getInstallChannel, offersUpdateCheck, platformOwnsUpdates } from "./install-channel";
-import { getSelectedDesktopSource, registerIpcHandlers } from "./ipc/handlers";
+import {
+	exportDiagnosticFile,
+	getSelectedDesktopSource,
+	registerIpcHandlers,
+} from "./ipc/handlers";
 import { installMainProcessErrorGuards } from "./main-process-errors";
 import { registerSttIpc, shutdownStt } from "./stt";
 import { checkLatestRelease } from "./update-checker";
@@ -211,6 +215,11 @@ function setupApplicationMenu() {
 					role: "about",
 					label: mainT("common", "actions.about") || "About OpenScreen",
 				},
+				{ type: "separator" as const },
+				{
+					label: mainT("common", "actions.saveDiagnostics") || "Save Diagnostics",
+					click: runSaveDiagnostics,
+				},
 				// Omitted entirely — here, in the Help menu and in the tray — where a package
 				// manager owns the update. See `canOfferUpdateCheck`.
 				...(canOfferUpdateCheck()
@@ -369,6 +378,11 @@ function setupApplicationMenu() {
 					label: mainT("common", "actions.about") || "About OpenScreen",
 					click: runAboutDialog,
 				},
+				{ type: "separator" as const },
+				{
+					label: mainT("common", "actions.saveDiagnostics") || "Save Diagnostics",
+					click: runSaveDiagnostics,
+				},
 			],
 		});
 	}
@@ -519,6 +533,47 @@ function runUpdateCheck() {
 	});
 }
 
+/**
+ * Menu and tray entry point for exporting a diagnostic bundle. The backend
+ * (`exportDiagnosticFile`) and its "Save Diagnostics" label already existed —
+ * nothing in the app ever called it (getopenscreen/openscreen#460). Reveals
+ * the written file on success, the same confirmation the export flow's "Show
+ * in folder" gives, so there is no need for a second dialog on top of the
+ * native Save dialog the user already went through.
+ *
+ * No renderer `projectState`/`logs` to attach from here, unlike the in-app
+ * crash path this shares a payload shape with — the diagnostic value for a
+ * capture bug is almost entirely `helperOutput`/`mainProcessLogs`, which
+ * `exportDiagnosticFile` reads straight from the main process regardless.
+ */
+function runSaveDiagnostics() {
+	exportDiagnosticFile({ error: "Manual diagnostic export", projectState: null, logs: [] })
+		.then((result) => {
+			if (result.canceled) return;
+			if (!result.success) {
+				// exportDiagnosticFile resolves rather than rejects on a write
+				// failure, so this is the branch that turns "user picked a save
+				// location and got silence" into a visible error instead of a
+				// menu action that looks like it did nothing.
+				showMessageBox({
+					type: "error",
+					title: PRODUCT_NAME,
+					message: mainT("dialogs", "export.failed") || "Export Failed",
+					detail: result.error,
+				}).catch((error) => {
+					console.error("[diagnostics] failure dialog failed", error);
+				});
+				return;
+			}
+			if (result.path) {
+				shell.showItemInFolder(result.path);
+			}
+		})
+		.catch((error) => {
+			console.error("[diagnostics] save failed", error);
+		});
+}
+
 /** Mirrors the flag that already drives the tray icon. An update must never interrupt a take —
  *  and on Windows it physically cannot, because the capture helpers spawn from inside the
  *  install directory and NSIS cannot overwrite a running .exe. */
@@ -730,6 +785,14 @@ function updateTrayMenu(recording: boolean = false) {
 							label: mainT("common", "actions.about") || "About OpenScreen",
 							click: runAboutDialog,
 						},
+				// Right next to About, and reachable without opening any window: this is the
+				// one place in the app most likely to still be usable right after a recording
+				// failed to stop, which is exactly when the [stop-timing]/encoder-selection
+				// lines this exports are worth the most (getopenscreen/openscreen#460).
+				{
+					label: mainT("common", "actions.saveDiagnostics") || "Save Diagnostics",
+					click: runSaveDiagnostics,
+				},
 				{ type: "separator" as const },
 				{
 					label: mainT("common", "actions.quit") || "Quit",
diff --git a/electron/native/wgc-capture/src/main.cpp b/electron/native/wgc-capture/src/main.cpp
index c64d7970..a9e21d45 100644
--- a/electron/native/wgc-capture/src/main.cpp
+++ b/electron/native/wgc-capture/src/main.cpp
@@ -682,6 +682,16 @@ int main(int argc, char* argv[]) {
     // ordinary hardware, so the stop path can be regression-tested at all.
     const int testStallReadbackMs =
         std::max(0, readEnvInt("OPENSCREEN_WGC_TEST_STALL_READBACK_MS", 0));
+    // Test-only: stall the WGC frame *callback* itself while it holds the
+    // same frame lock, rather than the writer's readback -- the shape
+    // getopenscreen/openscreen#460 actually reproduced on Intel HD 520
+    // ("A WGC frame callback did not finish"). Distinct from
+    // testStallReadbackMs above because quiesceCapture()'s drain only ever
+    // sees the callback side: a stall placed in the writer instead leaves
+    // callbacksInFlight_ at zero and wgcDrained true, which cannot exercise
+    // the video-writer-join skip this stall exists to test.
+    const int testStallFrameCallbackMs =
+        std::max(0, readEnvInt("OPENSCREEN_WGC_TEST_STALL_FRAME_CALLBACK_MS", 0));
 
     std::cout << "{\"event\":\"ready\",\"schemaVersion\":2}" << std::endl;
 
@@ -931,6 +941,18 @@ int main(int argc, char* argv[]) {
             }
         }
 
+        // Gated on an already-arrived first frame: main() blocks up to 10s
+        // waiting for firstFrameWritten before it will even print
+        // recording-started, a startup budget this stall is meant to outlast
+        // (it needs to still be asleep when `stop` arrives, seconds later).
+        // Stalling the first frame trips that unrelated timeout instead of
+        // reaching the steady-state shutdown path this exists to test, and
+        // does not match the real report either -- getopenscreen/openscreen
+        // #460's diagnostic shows recording-started succeeding before the
+        // hang.
+        if (testStallFrameCallbackMs > 0 && firstFrameWritten.load()) {
+            std::this_thread::sleep_for(std::chrono::milliseconds(testStallFrameCallbackMs));
+        }
         session.context()->CopyResource(latestFrameTexture.Get(), texture);
         latestFrameTimestampHns = timestampHns;
         if (!firstFrameWritten.exchange(true)) {
@@ -1420,8 +1442,47 @@ int main(int argc, char* argv[]) {
     }
     logStopStep("audio-mixer");
     beginStopStep("video-writer-join", stepBudgetMs);
-    stopVideoWriter();
-    logStopStep("video-writer-join");
+    if (wgcDrained) {
+        stopVideoWriter();
+        logStopStep("video-writer-join");
+    } else {
+        // wgc-quiesce already reported the frame callback stuck inside the
+        // driver (getopenscreen/openscreen#460 on Intel HD 520: a
+        // CopyResource that never returns), still holding the same
+        // frame-state `mutex` writeVideoFrames takes for its own
+        // per-iteration wait -- the one it also needs to notice
+        // stopRequested. Joining is not a step that can time out here, it is
+        // one that cannot ever succeed, and this is not the only step that
+        // assumed it would: encoder.finalize() below resets the very D3D
+        // device/context a still-blocked writer thread might resume touching
+        // the moment that lock frees, and quiesceCapture()/stop() already
+        // treat "leave everything alone and let process exit reclaim it" as
+        // the only safe response to exactly this state. So this ends the
+        // process here, on this thread, rather than pretending the rest of a
+        // clean shutdown is reachable -- which cost nothing extra before
+        // today: the same TerminateProcess happened anyway, just
+        // stepBudgetMs later, once this step's own watchdog gave up waiting
+        // on a join that could never return. detach() first, not because
+        // TerminateProcess needs it (it does not touch the C++ runtime, no
+        // std::thread destructor runs), but so nothing between here and the
+        // kill can trip over a still-joinable thread.
+        //
+        // The fragmented sink writes moof+mdat incrementally, roughly once a
+        // second, so this is not a new source of loss: whatever was already
+        // on disk before the callback wedged is on disk regardless of
+        // whether Finalize() ever runs, on this path or the slower one it
+        // replaces.
+        videoWriterThread.detach();
+        std::cerr << "[stop-timing] step=video-writer-join elapsed_ms=" << stopElapsedMs()
+                  << " phase=abandoned encode_stage=" << encoder.encodeStage()
+                  << " audio_stage=" << encoder.audioStage() << " reason=frame-callback-stuck"
+                  << std::endl;
+        std::cout << "{\"event\":\"stop-timeout\",\"schemaVersion\":2,\"step\":\"video-writer-join\"}"
+                  << std::endl;
+        std::cout.flush();
+        std::cerr.flush();
+        TerminateProcess(GetCurrentProcess(), 3);
+    }
     if (usesDxgiInput) {
         std::cerr << "[frame-drops] gpu_bridge_contended=" << contendedFrames.load() << std::endl;
     }
@@ -1430,7 +1491,9 @@ int main(int argc, char* argv[]) {
     // the encoder's GPU readback, and audioMixer->stop() joined the only other
     // thread that writes to it. MFEncoder's own writerMutex_ deliberately does
     // NOT cover copyFrameToBuffer, so finalizing before those joins would race
-    // the staging texture -- do not reorder these.
+    // the staging texture -- do not reorder these. Reaching this line at all
+    // means wgcDrained was true above: the branch that was not is a
+    // TerminateProcess call, not a fallthrough.
     beginStopStep("encoder-finalize", shutdownBudgetMs);
     const bool screenFinalized = encoder.finalize();
     logStopStep("encoder-finalize");
diff --git a/electron/native/wgc-capture/src/mf_encoder.cpp b/electron/native/wgc-capture/src/mf_encoder.cpp
index c1e5c2bb..4130b132 100644
--- a/electron/native/wgc-capture/src/mf_encoder.cpp
+++ b/electron/native/wgc-capture/src/mf_encoder.cpp
@@ -406,16 +406,17 @@ bool resolveStreamSinkIndex(IMFMediaSink* mediaSink, const GUID& majorType, DWOR
 
 // Did the video stream's encoder MFT actually land on hardware?
 //
-// BeginWriting() succeeding says nothing about this: on the "default" path
-// (see kVideoEncoderRuntime* in mf_encoder.h) no attribute asked for hardware
-// transforms, so Media Foundation is free to hand the sink writer a software
-// MFT even when a hardware one is registered and would have worked. The only
-// way to know which one it actually picked is to ask the pipeline it built,
-// after the fact -- IMFSinkWriterEx::GetTransformForStream walks the MFTs the
-// sink writer inserted for a stream, and a hardware MFT instance is required
-// to expose MFT_ENUM_HARDWARE_URL_Attribute on its own attribute store (not
-// just on the IMFActivate MFTEnumEx returns), which is what distinguishes it
-// from a software one at this point.
+// BeginWriting() succeeding says nothing about this: even on the "default"
+// path (see kVideoEncoderRuntime* in mf_encoder.h), which does now ask for
+// MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS, that is a request and not a
+// guarantee -- Media Foundation is still free to hand the sink writer a
+// software MFT when no hardware one is registered or the driver refuses it.
+// The only way to know which one it actually picked is to ask the pipeline it
+// built, after the fact -- IMFSinkWriterEx::GetTransformForStream walks the
+// MFTs the sink writer inserted for a stream, and a hardware MFT instance is
+// required to expose MFT_ENUM_HARDWARE_URL_Attribute on its own attribute
+// store (not just on the IMFActivate MFTEnumEx returns), which is what
+// distinguishes it from a software one at this point.
 //
 // Every failure path here returns "unknown" rather than guessing: this runs
 // after the sink writer is already committed to, so it must never be able to
diff --git a/scripts/test-windows-wgc-helper.mjs b/scripts/test-windows-wgc-helper.mjs
index 1e513c72..ee40838e 100644
--- a/scripts/test-windows-wgc-helper.mjs
+++ b/scripts/test-windows-wgc-helper.mjs
@@ -45,6 +45,20 @@ const WITH_STALLED_READBACK =
 	process.env.OPENSCREEN_WGC_TEST_STALL_READBACK === "true" ||
 	process.argv.includes("--stall-readback");
 const STALL_READBACK_MS = Number(process.env[STALL_READBACK_ENV] ?? 60_000);
+const STALL_FRAME_CALLBACK_ENV = "OPENSCREEN_WGC_TEST_STALL_FRAME_CALLBACK_MS";
+/**
+ * Reproduces getopenscreen/openscreen#460 on ordinary hardware: stalls the WGC
+ * frame *callback* itself while it holds the frame lock, the shape that issue
+ * actually reproduced on Intel HD 520 ("A WGC frame callback did not finish").
+ * Distinct from WITH_STALLED_READBACK above -- that stalls the writer's own
+ * readback, which quiesceCapture()'s drain cannot see (callbacksInFlight_
+ * stays at zero), so it cannot exercise the video-writer-join skip this stall
+ * exists to test.
+ */
+const WITH_STALLED_FRAME_CALLBACK =
+	process.env.OPENSCREEN_WGC_TEST_STALL_FRAME_CALLBACK === "true" ||
+	process.argv.includes("--stall-frame-callback");
+const STALL_FRAME_CALLBACK_MS = Number(process.env[STALL_FRAME_CALLBACK_ENV] ?? 60_000);
 const STOP_BUDGET_ENV = "OPENSCREEN_WGC_STOP_BUDGET_MS";
 /**
  * The helper's global shutdown ceiling, pinned into its environment below so
@@ -64,11 +78,15 @@ if (WITH_SOFTWARE_ENCODER && WITH_SOFTWARE_FALLBACK) {
 	throw new Error("--software-encoder and --software-fallback are mutually exclusive");
 }
 
-function runHelper(config, { injectDefaultSinkWriterFailure = false, stallReadbackMs = 0 } = {}) {
+function runHelper(
+	config,
+	{ injectDefaultSinkWriterFailure = false, stallReadbackMs = 0, stallFrameCallbackMs = 0 } = {},
+) {
 	return new Promise((resolve, reject) => {
 		const env = { ...process.env };
 		delete env[INJECT_DEFAULT_SINK_WRITER_FAILURE_ENV];
 		delete env[STALL_READBACK_ENV];
+		delete env[STALL_FRAME_CALLBACK_ENV];
 		env[STOP_BUDGET_ENV] = String(STOP_BUDGET_MS);
 		if (injectDefaultSinkWriterFailure) {
 			env[INJECT_DEFAULT_SINK_WRITER_FAILURE_ENV] = "1";
@@ -76,6 +94,9 @@ function runHelper(config, { injectDefaultSinkWriterFailure = false, stallReadba
 		if (stallReadbackMs > 0) {
 			env[STALL_READBACK_ENV] = String(stallReadbackMs);
 		}
+		if (stallFrameCallbackMs > 0) {
+			env[STALL_FRAME_CALLBACK_ENV] = String(stallFrameCallbackMs);
+		}
 		const child = spawn(HELPER_PATH, [JSON.stringify(config)], {
 			env,
 			stdio: ["pipe", "pipe", "pipe"],
@@ -213,6 +234,48 @@ function startFixtureWindow() {
 	});
 }
 
+/**
+ * Windows Graphics Capture delivers frames on compositor damage, not on a
+ * fixed clock -- on a genuinely idle desktop the frame pool can go a full
+ * test run without ever firing FrameArrived once. That is invisible to most
+ * of this harness, which just needs *a* frame eventually, but the
+ * stalled-frame-callback regression check needs one to land *inside* the
+ * DURATION_MS window specifically, so the stall this injects is actually the
+ * thing holding the frame lock when `stop` arrives.
+ *
+ * Moving the cursor alone does not reliably do this: most modern GPU/driver
+ * combinations composite the cursor on its own hardware overlay plane, so
+ * repositioning it never touches the desktop bitmap WGC captures (confirmed
+ * empirically here -- frames=0 with a cursor-only nudge running the whole
+ * test). A visible window changing position is not optional the way the
+ * cursor is; DWM has to redraw the area it moved across. Returns a stop
+ * function; always call it, paired failure or not, or the window and its
+ * PowerShell host outlive the test process.
+ */
+function startScreenActivity() {
+	const child = spawn(
+		"powershell",
+		[
+			"-NoProfile",
+			"-Command",
+			"Add-Type -AssemblyName System.Windows.Forms; " +
+				"$f = New-Object System.Windows.Forms.Form; " +
+				"$f.StartPosition = 'Manual'; $f.Location = New-Object System.Drawing.Point(0,0); " +
+				"$f.Size = New-Object System.Drawing.Size(200,200); " +
+				"$f.TopMost = $true; $f.Show(); " +
+				"$x = 0; " +
+				"while ($true) { " +
+				"$f.Location = New-Object System.Drawing.Point($x, 0); " +
+				"$x = ($x + 20) % 200; " +
+				"[System.Windows.Forms.Application]::DoEvents(); " +
+				"Start-Sleep -Milliseconds 100; " +
+				"}",
+		],
+		{ stdio: ["ignore", "ignore", "ignore"], windowsHide: false },
+	);
+	return () => child.kill();
+}
+
 function normalizeDeviceName(value) {
 	return value
 		.toLowerCase()
@@ -413,16 +476,19 @@ const config = {
 	},
 };
 
+const stopScreenActivity = WITH_STALLED_FRAME_CALLBACK ? startScreenActivity() : null;
 let result;
 try {
 	result = await runHelper(config, {
 		injectDefaultSinkWriterFailure: WITH_SOFTWARE_FALLBACK,
 		stallReadbackMs: WITH_STALLED_READBACK ? STALL_READBACK_MS : 0,
+		stallFrameCallbackMs: WITH_STALLED_FRAME_CALLBACK ? STALL_FRAME_CALLBACK_MS : 0,
 	});
 } finally {
 	if (fixtureWindow) {
 		fixtureWindow.child.kill();
 	}
+	stopScreenActivity?.();
 }
 
 // The regression check for issue #252. With the frame lock deliberately wedged
@@ -453,6 +519,51 @@ if (WITH_STALLED_READBACK) {
 	process.exit(0);
 }
 
+// The regression check for getopenscreen/openscreen#460: a frame callback
+// wedged inside the driver, confirmed on real hardware via a Save Diagnostics
+// report. Before the fix, video-writer-join burned its whole step budget
+// joining a thread parked behind that same stuck callback -- this asserts
+// both that the helper still exits promptly (not the ~13s that step's own
+// budget alone would cost) and that it took the specific skip path rather
+// than any other route to exiting.
+if (WITH_STALLED_FRAME_CALLBACK) {
+	if (result.stopHung) {
+		throw new Error(
+			`Helper survived ${STOP_HANG_LIMIT_MS}ms past "stop" with a stalled frame callback. ` +
+				"Its shutdown watchdog did not fire (issue #460).",
+		);
+	}
+	const steps = readStopTimingSteps(result.stderr);
+	if (!steps.includes("command-received")) {
+		throw new Error(`Helper never acknowledged "stop". Steps seen: ${steps.join(", ") || "none"}`);
+	}
+	if (!result.stderr.includes("reason=frame-callback-stuck")) {
+		throw new Error(
+			`Helper did not take the video-writer-join skip path. stderr:\n${result.stderr}`,
+		);
+	}
+	// wgc-quiesce's own drain is a fixed 5000ms, so a healthy skip lands
+	// there plus the near-instant audio/microphone/webcam steps -- nowhere
+	// near the ~13s (5s drain + the 8s step budget) the join it replaces
+	// would have cost before this fix.
+	const STALLED_FRAME_CALLBACK_LATENCY_BUDGET_MS = 10_000;
+	if (
+		result.stopLatencyMs !== null &&
+		result.stopLatencyMs > STALLED_FRAME_CALLBACK_LATENCY_BUDGET_MS
+	) {
+		throw new Error(
+			`Stop took ${result.stopLatencyMs}ms with a stalled frame callback, over the ` +
+				`${STALLED_FRAME_CALLBACK_LATENCY_BUDGET_MS}ms budget the video-writer-join skip should keep it under.`,
+		);
+	}
+	console.log("WGC helper stalled-frame-callback stop check passed", {
+		stopLatencyMs: result.stopLatencyMs,
+		steps,
+	});
+	fs.rmSync(outputPath, { force: true });
+	process.exit(0);
+}
+
 assertStopWasClean(result);
 
 if (result.code !== 0) {
diff --git a/src/i18n/locales/ar/common.json b/src/i18n/locales/ar/common.json
index ef0d6736..b63cd026 100644
--- a/src/i18n/locales/ar/common.json
+++ b/src/i18n/locales/ar/common.json
@@ -40,7 +40,8 @@
 		"services": "خدمات",
 		"hide": "إخفاء OpenScreen",
 		"hideOthers": "إخفاء الآخرين",
-		"unhide": "إظهار الكل"
+		"unhide": "إظهار الكل",
+		"saveDiagnostics": "حفظ التشخيصات"
 	},
 	"updates": {
 		"available": "يتوفر OpenScreen {{latestVersion}}. الإصدار المثبت هو {{currentVersion}}.",
diff --git a/src/i18n/locales/en/common.json b/src/i18n/locales/en/common.json
index 4f303ee6..6eac9583 100644
--- a/src/i18n/locales/en/common.json
+++ b/src/i18n/locales/en/common.json
@@ -40,7 +40,8 @@
 		"services": "Services",
 		"hide": "Hide OpenScreen",
 		"hideOthers": "Hide Others",
-		"unhide": "Show All"
+		"unhide": "Show All",
+		"saveDiagnostics": "Save Diagnostics"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} is available. You are using {{currentVersion}}.",
diff --git a/src/i18n/locales/es/common.json b/src/i18n/locales/es/common.json
index 3c92583a..29a36426 100644
--- a/src/i18n/locales/es/common.json
+++ b/src/i18n/locales/es/common.json
@@ -40,7 +40,8 @@
 		"services": "Servicios",
 		"hide": "Ocultar OpenScreen",
 		"hideOthers": "Ocultar otros",
-		"unhide": "Mostrar todo"
+		"unhide": "Mostrar todo",
+		"saveDiagnostics": "Guardar diagnósticos"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} está disponible. Estás usando {{currentVersion}}.",
diff --git a/src/i18n/locales/fr/common.json b/src/i18n/locales/fr/common.json
index de72f313..c74ef66b 100644
--- a/src/i18n/locales/fr/common.json
+++ b/src/i18n/locales/fr/common.json
@@ -40,7 +40,8 @@
 		"services": "Services",
 		"hide": "Masquer OpenScreen",
 		"hideOthers": "Masquer les autres",
-		"unhide": "Tout afficher"
+		"unhide": "Tout afficher",
+		"saveDiagnostics": "Enregistrer les diagnostics"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} est disponible. Vous utilisez la version {{currentVersion}}.",
diff --git a/src/i18n/locales/it/common.json b/src/i18n/locales/it/common.json
index df18ace1..24f10fc6 100644
--- a/src/i18n/locales/it/common.json
+++ b/src/i18n/locales/it/common.json
@@ -40,7 +40,8 @@
 		"services": "Servizi",
 		"hide": "Nascondi OpenScreen",
 		"hideOthers": "Nascondi gli altri",
-		"unhide": "Mostra tutto"
+		"unhide": "Mostra tutto",
+		"saveDiagnostics": "Salva dati diagnostici"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} è disponibile. Stai usando la versione {{currentVersion}}.",
diff --git a/src/i18n/locales/ja-JP/common.json b/src/i18n/locales/ja-JP/common.json
index 88899975..0d3ca001 100644
--- a/src/i18n/locales/ja-JP/common.json
+++ b/src/i18n/locales/ja-JP/common.json
@@ -40,7 +40,8 @@
 		"services": "サービス",
 		"hide": "OpenScreenを隠す",
 		"hideOthers": "ほかを隠す",
-		"unhide": "すべて表示"
+		"unhide": "すべて表示",
+		"saveDiagnostics": "診断情報を保存"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} を利用できます。現在のバージョンは {{currentVersion}} です。",
diff --git a/src/i18n/locales/ko-KR/common.json b/src/i18n/locales/ko-KR/common.json
index 964fdd63..98d025d9 100644
--- a/src/i18n/locales/ko-KR/common.json
+++ b/src/i18n/locales/ko-KR/common.json
@@ -40,7 +40,8 @@
 		"services": "서비스",
 		"hide": "OpenScreen 숨기기",
 		"hideOthers": "다른 항목 숨기기",
-		"unhide": "모두 보기"
+		"unhide": "모두 보기",
+		"saveDiagnostics": "진단 정보 저장"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} 버전을 사용할 수 있습니다. 현재 버전은 {{currentVersion}}입니다.",
diff --git a/src/i18n/locales/pt-BR/common.json b/src/i18n/locales/pt-BR/common.json
index af25d126..d74e5b21 100644
--- a/src/i18n/locales/pt-BR/common.json
+++ b/src/i18n/locales/pt-BR/common.json
@@ -40,7 +40,8 @@
 		"services": "Serviços",
 		"hide": "Ocultar OpenScreen",
 		"hideOthers": "Ocultar Outros",
-		"unhide": "Mostrar Todos"
+		"unhide": "Mostrar Todos",
+		"saveDiagnostics": "Salvar Diagnósticos"
 	},
 	"updates": {
 		"available": "O OpenScreen {{latestVersion}} está disponível. Você está usando a versão {{currentVersion}}.",
diff --git a/src/i18n/locales/ru/common.json b/src/i18n/locales/ru/common.json
index d7ec15ae..141e8b98 100644
--- a/src/i18n/locales/ru/common.json
+++ b/src/i18n/locales/ru/common.json
@@ -40,7 +40,8 @@
 		"services": "Сервисы",
 		"hide": "Скрыть OpenScreen",
 		"hideOthers": "Скрыть остальные",
-		"unhide": "Показать все"
+		"unhide": "Показать все",
+		"saveDiagnostics": "Сохранить диагностику"
 	},
 	"updates": {
 		"available": "Доступен OpenScreen {{latestVersion}}. Установлена версия {{currentVersion}}.",
diff --git a/src/i18n/locales/tr/common.json b/src/i18n/locales/tr/common.json
index e36c2dc3..923079b1 100644
--- a/src/i18n/locales/tr/common.json
+++ b/src/i18n/locales/tr/common.json
@@ -40,7 +40,8 @@
 		"services": "Servisler",
 		"hide": "OpenScreen’i Gizle",
 		"hideOthers": "Diğerlerini Gizle",
-		"unhide": "Tümünü Göster"
+		"unhide": "Tümünü Göster",
+		"saveDiagnostics": "Teşhis Verilerini Kaydet"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} kullanılabilir. Mevcut sürümünüz {{currentVersion}}.",
diff --git a/src/i18n/locales/vi/common.json b/src/i18n/locales/vi/common.json
index 544cf3b8..089cf992 100644
--- a/src/i18n/locales/vi/common.json
+++ b/src/i18n/locales/vi/common.json
@@ -40,7 +40,8 @@
 		"services": "Dịch vụ",
 		"hide": "Ẩn OpenScreen",
 		"hideOthers": "Ẩn ứng dụng khác",
-		"unhide": "Hiển thị tất cả"
+		"unhide": "Hiển thị tất cả",
+		"saveDiagnostics": "Lưu thông tin chẩn đoán"
 	},
 	"updates": {
 		"available": "Đã có OpenScreen {{latestVersion}}. Bạn đang dùng phiên bản {{currentVersion}}.",
diff --git a/src/i18n/locales/zh-CN/common.json b/src/i18n/locales/zh-CN/common.json
index 30b018cc..0a7b2bd9 100644
--- a/src/i18n/locales/zh-CN/common.json
+++ b/src/i18n/locales/zh-CN/common.json
@@ -40,7 +40,8 @@
 		"services": "服务",
 		"hide": "隐藏 OpenScreen",
 		"hideOthers": "隐藏其他",
-		"unhide": "显示全部"
+		"unhide": "显示全部",
+		"saveDiagnostics": "保存诊断信息"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} 已发布。当前版本为 {{currentVersion}}。",
diff --git a/src/i18n/locales/zh-TW/common.json b/src/i18n/locales/zh-TW/common.json
index 07d66259..c54dc17e 100644
--- a/src/i18n/locales/zh-TW/common.json
+++ b/src/i18n/locales/zh-TW/common.json
@@ -40,7 +40,8 @@
 		"services": "服務",
 		"hide": "隱藏 OpenScreen",
 		"hideOthers": "隱藏其他",
-		"unhide": "全部顯示"
+		"unhide": "全部顯示",
+		"saveDiagnostics": "儲存診斷資料"
 	},
 	"updates": {
 		"available": "OpenScreen {{latestVersion}} 已推出。目前版本為 {{currentVersion}}。",