diff --git a/src/extension.ts b/src/extension.ts
index f0e84a331..a8f7f3514 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -821,12 +821,16 @@ export async function activate(context: vscode.ExtensionContext) {
     context.subscriptions.push(
         vscode.commands.registerCommand("codex-editor-extension.generateTranscriptions", async () => {
             const countInput = await vscode.window.showInputBox({
-                prompt: "How many cells to transcribe?",
-                placeHolder: "e.g., 5",
-                validateInput: (val) => (val && !isNaN(Number(val)) && Number(val) >= 1 ? undefined : "Enter a positive number"),
+                prompt: "How many cells to transcribe? (0 or blank = all untranscribed cells)",
+                placeHolder: "0 for all, or a specific number",
+                value: "0",
+                validateInput: (val) => {
+                    if (!val || val.trim() === "") return undefined;
+                    return !isNaN(Number(val)) && Number(val) >= 0 ? undefined : "Enter 0 for all, or a positive number";
+                },
             });
-            if (!countInput) return;
-            const count = Math.max(1, Math.floor(Number(countInput)));
+            if (countInput === undefined) return; // user cancelled
+            const count = Math.max(0, Math.floor(Number(countInput || 0)));
 
             const provider = GlobalProvider.getInstance().getProvider("codex-cell-editor") as CodexCellEditorProvider | undefined;
             if (!provider) {
@@ -835,7 +839,10 @@ export async function activate(context: vscode.ExtensionContext) {
             }
 
             provider.postMessageToWebviews({ type: "startBatchTranscription", content: { count } } as any);
-            vscode.window.showInformationMessage(`Starting transcription for up to ${count} cells...`);
+            const label = count > 0 ? `up to ${count}` : "all untranscribed";
+            vscode.window.showInformationMessage(
+                `Starting transcription for ${label} cells... First request may take ~45s to warm up.`
+            );
         })
     );
 
diff --git a/src/providers/NewSourceUploader/NewSourceUploaderProvider.ts b/src/providers/NewSourceUploader/NewSourceUploaderProvider.ts
index ec8a5f52c..2b76b4464 100644
--- a/src/providers/NewSourceUploader/NewSourceUploaderProvider.ts
+++ b/src/providers/NewSourceUploader/NewSourceUploaderProvider.ts
@@ -1653,7 +1653,13 @@ export class NewSourceUploaderProvider implements vscode.CustomTextEditorProvide
                     processedCells.set(paratextId, paratextCell);
                     paratextCount++;
                 } else if (alignedCell.notebookCell) {
-                    const targetId = alignedCell.importedContent.id;
+                    // Use the matched target cell's ID (from the aligner) to preserve
+                    // source-to-target linkage. The imported content may have a different
+                    // UUID generated during re-parsing, but the existing target cell's ID
+                    // is what matches the source notebook.
+                    const targetId = alignedCell.notebookCell.metadata?.id
+                        || alignedCell.notebookCell.id
+                        || alignedCell.importedContent.id;
                     const existingCell = existingCellsMap.get(targetId);
                     const existingValue = existingCell?.value ?? alignedCell.notebookCell.value ?? "";
 
@@ -1703,7 +1709,9 @@ export class NewSourceUploaderProvider implements vscode.CustomTextEditorProvide
                         newCells.push(paratextCell);
                     }
                 } else if (alignedCell.notebookCell) {
-                    const targetId = alignedCell.importedContent.id;
+                    const targetId = alignedCell.notebookCell.metadata?.id
+                        || alignedCell.notebookCell.id
+                        || alignedCell.importedContent.id;
                     const processedCell = processedCells.get(targetId);
 
                     if (processedCell) {
diff --git a/src/providers/codexCellEditorProvider/codexCellEditorMessagehandling.ts b/src/providers/codexCellEditorProvider/codexCellEditorMessagehandling.ts
index 6bd5465aa..944372811 100644
--- a/src/providers/codexCellEditorProvider/codexCellEditorMessagehandling.ts
+++ b/src/providers/codexCellEditorProvider/codexCellEditorMessagehandling.ts
@@ -394,10 +394,11 @@ const messageHandlers: Record<string, (ctx: MessageHandlerContext) => Promise<vo
                 console.error(`[getAsrConfig] This will cause transcription to fail. Please check authentication status.`);
             }
 
-            debug(`[getAsrConfig] Sending config: endpoint=${endpoint}, hasToken=${!!authToken}`);
+            const language = vscode.workspace.getConfiguration("codex-editor-extension").get<string>("asrLanguage", "eng");
+            debug(`[getAsrConfig] Sending config: endpoint=${endpoint}, hasToken=${!!authToken}, language=${language}`);
             safePostMessageToPanel(webviewPanel, {
                 type: "asrConfig",
-                content: { endpoint, authToken }
+                content: { endpoint, authToken, language }
             });
         } catch (error) {
             console.error("Error sending ASR config:", error);
@@ -417,6 +418,19 @@ const messageHandlers: Record<string, (ctx: MessageHandlerContext) => Promise<vo
         }
     },
 
+    requestBatchTranscription: async ({ event, webviewPanel, provider }) => {
+        const count = (event as any).content?.count ?? 0;
+        // Forward to the webview as a startBatchTranscription message
+        safePostMessageToPanel(webviewPanel, {
+            type: "startBatchTranscription",
+            content: { count },
+        } as any);
+        const label = count > 0 ? `up to ${count}` : "all untranscribed";
+        vscode.window.showInformationMessage(
+            `Starting transcription for ${label} cells... First request may take ~45s to warm up.`
+        );
+    },
+
     updateCellAfterTranscription: async ({ event, document, webviewPanel, provider }) => {
         const typedEvent = event as Extract<EditorPostMessages, { command: "updateCellAfterTranscription"; }>;
         const { cellId, transcribedText, language } = typedEvent.content;
diff --git a/webviews/codex-webviews/src/CodexCellEditor/AudioWaveformWithTranscription.tsx b/webviews/codex-webviews/src/CodexCellEditor/AudioWaveformWithTranscription.tsx
index e658762c4..47978831f 100644
--- a/webviews/codex-webviews/src/CodexCellEditor/AudioWaveformWithTranscription.tsx
+++ b/webviews/codex-webviews/src/CodexCellEditor/AudioWaveformWithTranscription.tsx
@@ -33,6 +33,7 @@ interface AudioWaveformWithTranscriptionProps {
     isTranscribing: boolean;
     transcriptionProgress: number;
     onTranscribe: () => void;
+    onTranscribeAll?: () => void;
     onInsertTranscription: () => void;
     disabled?: boolean;
     onRequestRemove?: () => void;
@@ -50,6 +51,7 @@ const AudioWaveformWithTranscription: React.FC<AudioWaveformWithTranscriptionPro
     isTranscribing,
     transcriptionProgress,
     onTranscribe,
+    onTranscribeAll,
     onInsertTranscription,
     disabled = false,
     onRequestRemove,
@@ -341,16 +343,30 @@ const AudioWaveformWithTranscription: React.FC<AudioWaveformWithTranscriptionPro
             {/* Action buttons at bottom */}
             <div className="flex flex-wrap items-center justify-center gap-2 px-2">
                 {!transcription && !isTranscribing && (
-                    <Button
-                        onClick={onTranscribe}
-                        disabled={disabled || (!audioUrl && !audioBlob)}
-                        variant="outline"
-                        className="h-8 px-2 text-xs text-[var(--vscode-button-background)] border-[var(--vscode-button-background)]/20 hover:bg-[var(--vscode-button-background)]/10"
-                        title="Transcribe Audio"
-                    >
-                        <MessageCircle className="h-3 w-3" />
-                        <span className="ml-1">Transcribe</span>
-                    </Button>
+                    <>
+                        <Button
+                            onClick={onTranscribe}
+                            disabled={disabled || (!audioUrl && !audioBlob)}
+                            variant="outline"
+                            className="h-8 px-2 text-xs text-[var(--vscode-button-background)] border-[var(--vscode-button-background)]/20 hover:bg-[var(--vscode-button-background)]/10"
+                            title="Transcribe this cell"
+                        >
+                            <MessageCircle className="h-3 w-3" />
+                            <span className="ml-1">Transcribe</span>
+                        </Button>
+                        {onTranscribeAll && (
+                            <Button
+                                onClick={onTranscribeAll}
+                                disabled={disabled}
+                                variant="outline"
+                                className="h-8 px-2 text-xs text-[var(--vscode-button-background)] border-[var(--vscode-button-background)]/20 hover:bg-[var(--vscode-button-background)]/10"
+                                title="Transcribe all untranscribed cells (recommended — avoids repeated cold starts)"
+                            >
+                                <MessageCircle className="h-3 w-3" />
+                                <span className="ml-1">Transcribe All</span>
+                            </Button>
+                        )}
+                    </>
                 )}
                 <Button
                     variant="outline"
diff --git a/webviews/codex-webviews/src/CodexCellEditor/CodexCellEditor.tsx b/webviews/codex-webviews/src/CodexCellEditor/CodexCellEditor.tsx
index 4d3d11a8f..d7e2b7b9e 100755
--- a/webviews/codex-webviews/src/CodexCellEditor/CodexCellEditor.tsx
+++ b/webviews/codex-webviews/src/CodexCellEditor/CodexCellEditor.tsx
@@ -457,6 +457,11 @@ const CodexCellEditor: React.FC = () => {
                     const targetCount = Math.max(0, message.content.count | 0);
                     const specificCellId: string | undefined = (message as any)?.content?.cellId;
                     let completed = 0;
+                    // Create a single client for the entire batch to reuse the warmed Modal container
+                    const client = new WhisperTranscriptionClient(
+                        wsEndpoint,
+                        asrConfig.authToken
+                    );
                     for (const unit of translationUnits) {
                         if (targetCount > 0 && completed >= targetCount) break;
                         const cellId = unit.cellMarkers[0];
@@ -508,11 +513,7 @@ const CodexCellEditor: React.FC = () => {
                         // Transcribe
                         debug(
                             "batchTranscription",
-                            `Creating client for cell ${cellId}: endpoint=${wsEndpoint}, hasToken=${!!asrConfig.authToken}`
-                        );
-                        const client = new WhisperTranscriptionClient(
-                            wsEndpoint,
-                            asrConfig.authToken
+                            `Transcribing cell ${cellId}: endpoint=${wsEndpoint}, hasToken=${!!asrConfig.authToken}`
                         );
                         try {
                             // Mark cell as transcribing for UI feedback
@@ -521,7 +522,7 @@ const CodexCellEditor: React.FC = () => {
                                 next.add(cellId);
                                 return next;
                             });
-                            const result = await client.transcribe(blob);
+                            const result = await client.transcribe(blob, 60000, asrConfig.language);
                             const text = (result.text || "").trim();
                             if (text) {
                                 vscode.postMessage({
@@ -529,7 +530,7 @@ const CodexCellEditor: React.FC = () => {
                                     content: {
                                         cellId,
                                         transcribedText: text,
-                                        language: "unknown",
+                                        language: asrConfig.language || "unknown",
                                     },
                                 } as unknown as EditorPostMessages);
 
diff --git a/webviews/codex-webviews/src/CodexCellEditor/TextCellEditor.tsx b/webviews/codex-webviews/src/CodexCellEditor/TextCellEditor.tsx
index c87fb93bc..f74a6e7c5 100644
--- a/webviews/codex-webviews/src/CodexCellEditor/TextCellEditor.tsx
+++ b/webviews/codex-webviews/src/CodexCellEditor/TextCellEditor.tsx
@@ -1350,6 +1350,14 @@ const CellEditor: React.FC<CellEditorProps> = ({
         }
     });
 
+    const handleTranscribeAll = () => {
+        // Trigger batch transcription for all untranscribed cells via the extension
+        window.vscodeApi.postMessage({
+            command: "requestBatchTranscription",
+            content: { count: 0 }, // 0 = all untranscribed cells
+        });
+    };
+
     const handleTranscribeAudio = async () => {
         // Check connectivity first
         if (!navigator.onLine) {
@@ -1397,8 +1405,8 @@ const CellEditor: React.FC<CellEditorProps> = ({
                 setTranscriptionStatus(`Error: ${error}`);
             };
 
-            // Perform transcription
-            const result = await client.transcribe(audioBlob);
+            // Perform transcription with language hint
+            const result = await client.transcribe(audioBlob, 60000, asrConfig?.language);
 
             // Success - save transcription but don't automatically insert
             const transcribedText = result.text.trim();
@@ -1417,7 +1425,7 @@ const CellEditor: React.FC<CellEditorProps> = ({
                         content: {
                             cellId: cellMarkers[0],
                             transcribedText: transcribedText,
-                            language: "unknown",
+                            language: asrConfig?.language || "unknown",
                         },
                     };
                     window.vscodeApi.postMessage(messageContent);
@@ -2894,6 +2902,7 @@ const CellEditor: React.FC<CellEditorProps> = ({
                                             isTranscribing={isTranscribing}
                                             transcriptionProgress={transcriptionProgress}
                                             onTranscribe={handleTranscribeAudio}
+                                            onTranscribeAll={handleTranscribeAll}
                                             onInsertTranscription={handleInsertTranscription}
                                             onRequestRemove={() => setConfirmingDiscard(true)}
                                             onShowHistory={() => setShowAudioHistory(true)}
diff --git a/webviews/codex-webviews/src/CodexCellEditor/WhisperTranscriptionClient.ts b/webviews/codex-webviews/src/CodexCellEditor/WhisperTranscriptionClient.ts
index ed5ad761b..be856f0d3 100644
--- a/webviews/codex-webviews/src/CodexCellEditor/WhisperTranscriptionClient.ts
+++ b/webviews/codex-webviews/src/CodexCellEditor/WhisperTranscriptionClient.ts
@@ -11,7 +11,8 @@ export class WhisperTranscriptionClient {
 
     async transcribe(
         audioBlob: Blob,
-        timeoutMs: number = 60000
+        timeoutMs: number = 60000,
+        language?: string
     ): Promise<{ text: string; }> {
         try {
             // Create FormData with audio file
@@ -25,6 +26,9 @@ export class WhisperTranscriptionClient {
             if (this.authToken) {
                 url.searchParams.set("token", this.authToken);
             }
+            if (language) {
+                url.searchParams.set("lang", language);
+            }
 
             // Prepare headers
             const headers: HeadersInit = {};
diff --git a/webviews/codex-webviews/src/NewSourceUploader/importers/usfm/experimental/usfmCellAligner.test.ts b/webviews/codex-webviews/src/NewSourceUploader/importers/usfm/experimental/usfmCellAligner.test.ts
new file mode 100644
index 000000000..c9c0dc466
--- /dev/null
+++ b/webviews/codex-webviews/src/NewSourceUploader/importers/usfm/experimental/usfmCellAligner.test.ts
@@ -0,0 +1,110 @@
+import { describe, it, expect } from 'vitest';
+import { usfmCellAligner } from './usfmCellAligner';
+
+/**
+ * Simulates the ID resolution logic from handleWriteTranslation.
+ * This is the fix for issue #429: use the matched target cell's ID
+ * (from the aligner) instead of the imported content's new UUID.
+ */
+function resolveTargetId(alignedCell: { notebookCell: any; importedContent: { id: string } }) {
+    return alignedCell.notebookCell?.metadata?.id
+        || alignedCell.notebookCell?.id
+        || alignedCell.importedContent.id;
+}
+
+describe('usfmCellAligner', () => {
+    it('matches imported content to target cells by cellLabel', async () => {
+        // Simulate existing target cells (from .codex file, created during source import)
+        const targetCells = [
+            { id: 'uuid-target-1', value: '', metadata: { id: 'uuid-target-1', cellLabel: 'GEN 1:1' } },
+            { id: 'uuid-target-2', value: '', metadata: { id: 'uuid-target-2', cellLabel: 'GEN 1:2' } },
+            { id: 'uuid-target-3', value: '', metadata: { id: 'uuid-target-3', cellLabel: 'GEN 1:3' } },
+        ];
+
+        // Simulate imported content (from re-parsing the same file — NEW UUIDs)
+        const importedContent = [
+            { id: 'uuid-new-1', content: 'In the beginning...', cellLabel: 'GEN 1:1' },
+            { id: 'uuid-new-2', content: 'And the earth was...', cellLabel: 'GEN 1:2' },
+            { id: 'uuid-new-3', content: 'And God said...', cellLabel: 'GEN 1:3' },
+        ];
+
+        const aligned = await usfmCellAligner(targetCells, [], importedContent);
+
+        // All 3 should be matched
+        const matchedCells = aligned.filter(a => a.importedContent.content.trim() !== '');
+        expect(matchedCells).toHaveLength(3);
+
+        // Each aligned cell's notebookCell should be the EXISTING target cell
+        for (const cell of matchedCells) {
+            expect(cell.notebookCell).toBeDefined();
+            expect(cell.notebookCell.metadata.id).toMatch(/^uuid-target-/);
+        }
+
+        // The imported content still has the new UUIDs
+        for (const cell of matchedCells) {
+            expect(cell.importedContent.id).toMatch(/^uuid-new-/);
+        }
+    });
+
+    it('resolves target ID from matched notebook cell, not imported content (issue #429 fix)', async () => {
+        const targetCells = [
+            { id: 'uuid-target-1', value: '', metadata: { id: 'uuid-target-1', cellLabel: 'GEN 1:1' } },
+            { id: 'uuid-target-2', value: '', metadata: { id: 'uuid-target-2', cellLabel: 'GEN 1:2' } },
+        ];
+
+        const importedContent = [
+            { id: 'uuid-new-1', content: 'In the beginning...', cellLabel: 'GEN 1:1' },
+            { id: 'uuid-new-2', content: 'And the earth was...', cellLabel: 'GEN 1:2' },
+        ];
+
+        const aligned = await usfmCellAligner(targetCells, [], importedContent);
+        const matchedCells = aligned.filter(a => a.importedContent.content.trim() !== '');
+
+        // Simulate the handleWriteTranslation ID resolution (the fix)
+        for (let i = 0; i < matchedCells.length; i++) {
+            const targetId = resolveTargetId(matchedCells[i]);
+            // The resolved ID should be the EXISTING target cell's UUID, not the imported one
+            expect(targetId).toBe(`uuid-target-${i + 1}`);
+            expect(targetId).not.toBe(`uuid-new-${i + 1}`);
+        }
+    });
+
+    it('preserves unmatched target cells (paratext, headers)', async () => {
+        const targetCells = [
+            { id: 'uuid-header', value: 'Genesis', metadata: { id: 'uuid-header', cellLabel: 'GEN 0:\\id:0' } },
+            { id: 'uuid-target-1', value: '', metadata: { id: 'uuid-target-1', cellLabel: 'GEN 1:1' } },
+        ];
+
+        // Only verse content imported (versesOnly mode)
+        const importedContent = [
+            { id: 'uuid-new-1', content: 'In the beginning...', cellLabel: 'GEN 1:1' },
+        ];
+
+        const aligned = await usfmCellAligner(targetCells, [], importedContent);
+
+        // Should have 2 cells: 1 matched verse + 1 preserved header
+        expect(aligned).toHaveLength(2);
+
+        // The header cell should be preserved with its original ID
+        const headerCell = aligned.find(a =>
+            (a.notebookCell?.metadata?.id || a.importedContent.id) === 'uuid-header'
+        );
+        expect(headerCell).toBeDefined();
+    });
+
+    it('handles case-insensitive cellLabel matching', async () => {
+        const targetCells = [
+            { id: 'uuid-target-1', value: '', metadata: { id: 'uuid-target-1', cellLabel: 'gen 1:1' } },
+        ];
+
+        const importedContent = [
+            { id: 'uuid-new-1', content: 'In the beginning...', cellLabel: 'GEN 1:1' },
+        ];
+
+        const aligned = await usfmCellAligner(targetCells, [], importedContent);
+        const matchedCells = aligned.filter(a => a.importedContent.content === 'In the beginning...');
+
+        expect(matchedCells).toHaveLength(1);
+        expect(matchedCells[0].notebookCell.metadata.id).toBe('uuid-target-1');
+    });
+});