diff --git a/src/lib/ai-edition/document/insertion.test.ts b/src/lib/ai-edition/document/insertion.test.ts
index 2581c7f0a..f024f524f 100644
--- a/src/lib/ai-edition/document/insertion.test.ts
+++ b/src/lib/ai-edition/document/insertion.test.ts
@@ -125,6 +125,44 @@ describe("insertGeneratedClip", () => {
 			[5, 10],
 		]);
 	});
+
+	it("keeps the speed and Full Camera regions of the right half, and both sides of one across the cut (#1037)", () => {
+		const region = (id: string, startSec: number, endSec: number) => ({
+			id,
+			clipId: "c1",
+			sourceStartSec: startSec,
+			sourceEndSec: endSec,
+			startMs: startSec * 1000,
+			endMs: endSec * 1000,
+		});
+		const next = withInsertion(
+			doc({
+				legacyEditor: {
+					speedRegions: [
+						{ ...region("right", 6, 8), speed: 2 },
+						{ ...region("across", 3, 5), speed: 2 },
+					],
+					cameraFullscreenRegions: [region("right", 7, 9), region("across", 3, 5)],
+				},
+			} as Partial<AxcutDocument>),
+		);
+		const rightId = next.timeline.clips[2].id;
+		const spans = (rows: unknown) =>
+			(rows as { clipId: string; sourceStartSec: number; sourceEndSec: number }[])
+				.map((r) => [r.clipId === rightId ? "right" : r.clipId, r.sourceStartSec, r.sourceEndSec])
+				.sort((a, b) => Number(a[1]) - Number(b[1]));
+		const legacy = next.legacyEditor as Record<string, unknown>;
+		expect(spans(legacy.speedRegions)).toEqual([
+			["c1", 3, 4],
+			["right", 4, 5],
+			["right", 6, 8],
+		]);
+		expect(spans(legacy.cameraFullscreenRegions)).toEqual([
+			["c1", 3, 4],
+			["right", 4, 5],
+			["right", 7, 9],
+		]);
+	});
 });
 
 describe("removeGeneratedClips", () => {
diff --git a/src/lib/ai-edition/document/insertion.ts b/src/lib/ai-edition/document/insertion.ts
index 14de27197..58300c274 100644
--- a/src/lib/ai-edition/document/insertion.ts
+++ b/src/lib/ai-edition/document/insertion.ts
@@ -27,7 +27,7 @@ import {
 	isGeneratedAssetId,
 } from "../timeline/clip-parts";
 import { createId } from "./ids";
-import { rederiveRegionMs, removeClip, resequenceClips } from "./timeline";
+import { mapAllRegionCollections, rederiveRegionMs, removeClip, resequenceClips } from "./timeline";
 
 /** Where a new word goes relative to the word the caret was resting on. */
 export type InsertSide = "before" | "after";
@@ -133,11 +133,13 @@ function fanOutAnchors(document: AxcutDocument, from: string, to: string): Axcut
 		(rows ?? []).flatMap((row) =>
 			row.clipId === from ? [row, { ...row, id: createId("frag"), clipId: to }] : [row],
 		);
+	// Every modifier collection, through the one walk that knows them all (#1037: a hand-picked
+	// list here forgot speed and Full Camera). Audio is kept out of it and fanned out on its own:
+	// that walk also re-anchors the takes, which is `rederiveRegionMs`'s job once the ms are fresh.
+	const fanned = mapAllRegionCollections({ ...document, audioTracks: [] }, both);
 	return {
-		...document,
-		timeline: { ...document.timeline, trimRanges: both(document.timeline.trimRanges) },
-		zoomRanges: both(document.zoomRanges),
-		annotations: both(document.annotations),
+		...fanned,
+		timeline: { ...fanned.timeline, trimRanges: both(fanned.timeline.trimRanges) },
 		audioTracks: both(document.audioTracks),
 	};
 }
diff --git a/src/lib/ai-edition/document/timeline.ts b/src/lib/ai-edition/document/timeline.ts
index 0e3a6046a..ba256fd3b 100644
--- a/src/lib/ai-edition/document/timeline.ts
+++ b/src/lib/ai-edition/document/timeline.ts
@@ -353,7 +353,7 @@ type StoredRegion = {
 };
 
 /** Apply `fn` to all four modifier collections (document-level + legacyEditor envelopes). */
-function mapAllRegionCollections(
+export function mapAllRegionCollections(
 	document: AxcutDocument,
 	fn: (regions: StoredRegion[], prefix: string) => StoredRegion[],
 ): AxcutDocument {