diff --git a/A00_Common/design/design_pipeline_page.ts b/A00_Common/design/design_pipeline_page.ts
index d5dbe7cd8..5469ee5b7 100644
--- a/A00_Common/design/design_pipeline_page.ts
+++ b/A00_Common/design/design_pipeline_page.ts
@@ -27,6 +27,7 @@ import type {
   FollowPatch,
   PipelineInputs,
   PipelineOutputs,
+  PipelineRunRecord,
   PipelineStation,
   RouteDraft,
   StageFn,
@@ -122,12 +123,13 @@ export interface PagePipelineOptions {
   /** 노선 조작 뒤 follow 가 가게 관 · 구조물을 다시 씀(목록 · 알약 다시) — `far` = 새 노선에서
    *  `STRUCTURE_ROUTE_DRIFT_MAX_M` 넘게 먼 구조물 수(초안을 버려 되돌렸으면 0). */
   onFacilitiesFollowed?: (far: number) => void;
-  /** 노선 초안을 버림(349-0k) — 초안 전 상세(`saved` · 없으면 null)로 되돌림 · `stations` = 저장 노선 측점. */
+  /** 노선 초안을 버림(349-0k) — 초안 전 상세(`saved` · 없으면 null)로 되돌림 · `stations` = 저장 노선 측점 ·
+   *  돌려주는 값 = 되돌림 길 한 단어(묶음 기록 `restoreWhy`). 끝난 뒤 종단도가 저장 기준으로 돌아옴. */
   onDraftDropped?: (
     routeId: number,
     saved: SectionDetailResponse | null,
     stations: PipelineStation[],
-  ) => void;
+  ) => Promise<string>;
 }
 
 interface PagePipeline {
@@ -225,6 +227,9 @@ function createPagePipeline(
   /** 노선 초안 전 상세(종단도가 그리던 것) — 초안을 버리면 이것으로(다시 셈 없음 · 349-0k). */
   let restoreTo: SectionDetailResponse | null = null;
   let restoring = false;
+  /** 초안을 버린 차례 기록 · 되돌림이 끝나는 약속(종단도는 그 뒤 저장 기준으로 — 349-0l). */
+  let dropRun: Promise<PipelineRunRecord> | null = null;
+  let dropping: Promise<string> | null = null;
   /** 노선 초안 전 가게 관 · 구조물 — 초안 동안 follow 가 새 측점을 가게에 씀 · 초안을 버리면 이것으로. */
   let beforeDraft: Facilities | null = null;
   /** 묶음이 가게에 마지막으로 쓴 관 · 구조물 · 쓰는 동안(메아리 — 다시 입력으로 안 받음). */
@@ -260,7 +265,8 @@ function createPagePipeline(
       crossSource = { detail, source: pipelineCrossSource(projectId, detail, savedStations) };
     return crossSource.source;
   };
-  const crossStage = createCrossStage();
+  const groundDeps = groundStageDeps(projectId);
+  const crossStage = createCrossStage({ grid: groundDeps.grid }); // 미교차 넓힘 = 같은 지형 격자(349-0j)
   const haulStage = createHaulStage(projectId, () => savedSource().routeId ?? undefined);
   const pipe = createDesignPipeline({
     stages: {
@@ -280,7 +286,7 @@ function createPagePipeline(
         },
       }),
       stations: createStationsStage({ intervalM: options.stationIntervalM, types: () => types }),
-      ground: createGroundStage(groundStageDeps(projectId)),
+      ground: createGroundStage(groundDeps),
       planline: createPlanlineStage({ savedBase: () => savedSource().base, savedLine }),
       profile: profileStage,
       // 단면 유형 기본값 = 새 지형 상단측(서버 노선 저장 규칙) — 단계 본문은 그대로 부름
@@ -319,8 +325,19 @@ function createPagePipeline(
     const stations = (event.value as PipelineOutputs["ground"] | null)?.stations ?? [];
     const saved = restoreTo;
     restoreTo = null;
-    if (typeof routeId === "number" && stations.length)
-      queueMicrotask(() => options.onDraftDropped?.(routeId, saved, stations));
+    if (typeof routeId !== "number" || !stations.length || !options.onDraftDropped) return;
+    const drop = options.onDraftDropped;
+    const record = dropRun;
+    dropping = new Promise<string>((resolve) =>
+      queueMicrotask(
+        () => void drop(routeId, saved, stations).then(resolve, () => resolve("error")),
+      ),
+    );
+    void dropping.then((why) =>
+      record?.then((run) =>
+        Object.assign(run, { restored: why === "saved" || why === "unchanged", restoreWhy: why }),
+      ),
+    );
   });
   // 사용자 노선 조작 뒤 follow 가 다시 매긴 관 · 구조물 = 가게(목록 · 알약 · 횡단 보기가 바로 새 측점) ·
   // 초안을 버리면 초안 전 값 · 열 때(start 차례)는 안 씀 — 알림 밖(틱 뒤)에서 씀(쓰기 고리 막음과 안 부딪힘)
@@ -375,7 +392,15 @@ function createPagePipeline(
     const edits = (pipe.input("alignment") as AlignmentEdits | null) ?? emptyEdits();
     if (draft) draftAlignment.set("alignmentDraft", edits);
     else if (drawnDraft) markAlignmentSaved(DRAFT_ROUTE_ID); // 초안을 버림 — 노선 0 칸도 비움
-    if ((draft || drawnDraft) && base) link.adoptPipeline(base, edits, draft);
+    // 초안을 버린 차례 — 상세를 되돌린 뒤 저장 기준으로(그 전에 그리면 초안 상세를 낡음으로 봄 · 349-0l)
+    const after = !draft && event.generation === quietGeneration ? dropping : null;
+    if ((draft || drawnDraft) && base) {
+      if (after)
+        void after.then(
+          () => void (!pipe.input("route") && link.adoptPipeline(base, edits, false)),
+        );
+      else link.adoptPipeline(base, edits, draft);
+    }
     drawnDraft = draft;
   });
 
@@ -473,9 +498,9 @@ function createPagePipeline(
       const before = pipe.output("route")?.line ?? null;
       const after = draft ? draftLine(draft, plan?.min_radius_m ?? 0).line : savedLine();
       const generation = pipe.generation;
-      void pipe.update("route", draft, routeRange(before, after));
+      const run = pipe.update("route", draft, routeRange(before, after));
       restoring = !draft && !!stored && pipe.generation !== generation;
-      if (restoring) quietGeneration = pipe.generation;
+      if (restoring) [quietGeneration, dropRun, dropping] = [pipe.generation, run, null];
     },
   };
 
diff --git a/A00_Common/design/design_profile.ts b/A00_Common/design/design_profile.ts
index ef5f75fbe..2c8f7849f 100644
--- a/A00_Common/design/design_profile.ts
+++ b/A00_Common/design/design_profile.ts
@@ -638,11 +638,11 @@ export function createDesignProfile(ctx: DesignProfileContext) {
         store = preview = createProfileEditStore(pagePipeline.DRAFT_ROUTE_ID, edits, () =>
           rebuild(),
         );
-      if (!draft && store === preview)
-        store = createProfileEditStore(routeId, savedEdits, () => rebuild());
-      if (!draft) preview = null;
-      base = draft ? nextBase : listed();
-      rebuild();
+      if (draft) return void ((base = nextBase), rebuild());
+      if (store === preview) store = createProfileEditStore(routeId, savedEdits, () => rebuild());
+      [preview, base] = [null, listed()];
+      alignment = base && buildAlignment(base, store.edits()); // 그리기만 · 다시 셈 예약 없음(349-0l)
+      draw();
     },
     /** [확정] 직전에 호출한다. 편집이 없으면 아무 것도 하지 않는다. */
     async save(): Promise<void> {
diff --git a/A00_Common/design/design_view_profile.ts b/A00_Common/design/design_view_profile.ts
index 27de2179b..25a104ac4 100644
--- a/A00_Common/design/design_view_profile.ts
+++ b/A00_Common/design/design_view_profile.ts
@@ -529,13 +529,14 @@ export async function mountProfileView(
         onCorridorStale: () => sections.setCorridorPending(true),
         onFacilitiesFollowed: followFacilities,
         // 초안을 버림 — 초안 전 상세 그대로(349-0k) · 그 상세가 없거나(초안 둔 채 새로고침) 측점이 다르면 갈아끼움
-        onDraftDropped: (routeId, saved, stations) =>
-          void (async () => {
-            const back =
-              saved && (await restoreSectionDetail(activeProjectId, routeId, saved, stations));
-            if (!saved || (back && !back.same))
-              await swapSectionStations(activeProjectId, routeId, stations);
-          })(),
+        onDraftDropped: async (routeId, saved, stations) => {
+          const back =
+            saved && (await restoreSectionDetail(activeProjectId, routeId, saved, stations));
+          if (saved && !back) return "unchanged";
+          if (back?.same) return "saved";
+          await swapSectionStations(activeProjectId, routeId, stations);
+          return saved ? "stations" : "no-saved";
+        },
       }),
     });
 
diff --git a/A00_Common/design/logic/design_pipeline_types.ts b/A00_Common/design/logic/design_pipeline_types.ts
index d8fd3122c..49557f657 100644
--- a/A00_Common/design/logic/design_pipeline_types.ts
+++ b/A00_Common/design/logic/design_pipeline_types.ts
@@ -278,4 +278,8 @@ export interface PipelineRunRecord {
   totalMs: number;
   /** done = 브라우저 단계 끝 · dropped = 새 조작에 밀려 버림 · error = 단계가 던짐. */
   outcome: "running" | "done" | "dropped" | "error";
+  /** 노선 초안을 버린 차례(349-0l) — 초안 전 상세로 되돌렸나 · 까닭 한 단어(saved · unchanged · stations ·
+   *  no-saved · none). */
+  restored?: boolean;
+  restoreWhy?: string;
 }
diff --git a/resources/tester/helper_349_0k_undo_saved.cjs b/resources/tester/helper_349_0k_undo_saved.cjs
index 132b0786f..5394f9385 100644
--- a/resources/tester/helper_349_0k_undo_saved.cjs
+++ b/resources/tester/helper_349_0k_undo_saved.cjs
@@ -192,14 +192,14 @@ async function run() {
   pageMod.routeDraftBridge(P, link, {
     stationIntervalM: job.interval,
     // `design_view_profile` 의 onDraftDropped 그대로
-    onDraftDropped: (routeId, saved, stations) =>
-      void (async () => {
-        const back =
-          saved && (await sectionStore.restoreSectionDetail(P, routeId, saved, stations));
-        restores.push({ saved: !!saved, back: back ? { same: back.same } : null });
-        if (!saved || (back && !back.same))
-          await sectionStore.swapSectionStations(P, routeId, stations);
-      })(),
+    onDraftDropped: async (routeId, saved, stations) => {
+      const back = saved && (await sectionStore.restoreSectionDetail(P, routeId, saved, stations));
+      restores.push({ saved: !!saved, back: back ? { same: back.same } : null });
+      if (saved && !back) return "unchanged";
+      if (back?.same) return "saved";
+      await sectionStore.swapSectionStations(P, routeId, stations);
+      return saved ? "stations" : "no-saved";
+    },
   });
   // followSwap — 새 상세 → 종단도 render(처음부터 다시 · 비정규 측점) · 가게 stations → 갈아끼움
   const stopListen = sectionStore.subscribeSectionDetail(P, R, (next) => {
diff --git a/resources/tester/helper_349_0l_undo_draw.cjs b/resources/tester/helper_349_0l_undo_draw.cjs
new file mode 100644
index 000000000..9d9f49a8a
--- /dev/null
+++ b/resources/tester/helper_349_0l_undo_draw.cjs
@@ -0,0 +1,373 @@
+/* PLAN 349-0l sub7 헬퍼 — 열기 → 노선 꼭짓점 끌기 → 되돌리기 → 횡단 보기 → 종단 보기, 누가토량 · 측점 · 횡단이
+ * 열 때와 같음 · 다시 셈 0. 진짜 TS — 종단도(`design_profile` · 낡음 판정 → crossPreview 예약) · 계산 묶음 ·
+ * 상세 가게(`B06_Section_Section_Store`). 화면 부품(DOM · SVG · 오버레이 · 도구줄)과 서버 창구만 가짜 ·
+ * 그리기는 진짜 `renderProfile` 의 낡음 판정 줄만 · 다시 셈 창구(`refreshCrossDesigns`)는 부른 수를 세고 면적을
+ * 바꿈(서버와 다른 값 흉내). 검증_sub7 노선(관 11 · 구조물 1 은 시험이 관 자리에 놓음).
+ * 입력 argv[2] JSON · argv[3] 격자 이진. 결과 = 표준출력 JSON. 짝 = `test_349_0l_undo_draw.py`. */
+const fs = require("fs");
+const path = require("path");
+const ts = require(path.join(__dirname, "..", "..", "config", "node_modules", "typescript"));
+const CATALOG = require("./helper_322_catalog_module.cjs");
+
+const ROOT = path.join(__dirname, "..", "..");
+const job = JSON.parse(fs.readFileSync(process.argv[2], "utf8"));
+
+function memoryStorage() {
+  const map = new Map();
+  return {
+    getItem: (key) => (map.has(key) ? map.get(key) : null),
+    setItem: (key, value) => map.set(key, String(value)),
+    removeItem: (key) => map.delete(key),
+    key: (index) => [...map.keys()][index] ?? null,
+    get length() {
+      return map.size;
+    },
+  };
+}
+const windowBase = {
+  sessionStorage: memoryStorage(),
+  localStorage: memoryStorage(),
+  setTimeout,
+  clearTimeout,
+  addEventListener: () => undefined,
+  removeEventListener: () => undefined,
+};
+globalThis.window = new Proxy(windowBase, {
+  get: (t, key) => (key in t ? t[key] : undefined),
+  set: (t, key, value) => ((t[key] = value), true),
+});
+
+// 흙 배분 서버 — 늦게 답함 · 끊기면 버림
+globalThis.fetch = (url, init) =>
+  new Promise((resolve, reject) => {
+    const timer = setTimeout(
+      () => resolve({ ok: true, json: async () => ({ haul_plan: { blocks: [], url } }) }),
+      20,
+    );
+    init.signal.addEventListener("abort", () => {
+      clearTimeout(timer);
+      reject(new Error("aborted"));
+    });
+  });
+
+const STUBS = {};
+const cache = new Map();
+function loadTs(full) {
+  if (cache.has(full)) return cache.get(full);
+  const js = ts.transpileModule(fs.readFileSync(full, "utf8"), {
+    compilerOptions: { module: ts.ModuleKind.CommonJS, target: ts.ScriptTarget.ES2020 },
+  }).outputText;
+  const box = { exports: {} };
+  cache.set(full, box.exports);
+  const localRequire = (request) => {
+    if (CATALOG.isCatalogRequest(request)) return CATALOG;
+    const key = Object.keys(STUBS).find((name) => request.endsWith(name));
+    if (key) return STUBS[key];
+    if (request.startsWith("@config/")) return { API_BASE_URL: "http://fake" };
+    if (request.startsWith("@ui/")) return anyModule();
+    if (request.endsWith(".css")) return {};
+    if (request.endsWith(".json")) return require(path.join(path.dirname(full), request));
+    if (request.startsWith("@util/"))
+      return loadTs(path.join(ROOT, "common_util", `${request.slice(6)}.ts`));
+    if (request.startsWith(".")) return loadTs(path.join(path.dirname(full), `${request}.ts`));
+    return require(request);
+  };
+  new Function("exports", "module", "require", js)(box.exports, box, localRequire);
+  return box.exports;
+}
+const load = (...parts) => loadTs(path.join(ROOT, ...parts));
+
+const sampler = load("common_util", "common_util_surface_sampler.ts");
+const bytes = fs.readFileSync(process.argv[3]);
+const grid = sampler.parseDtmGrid(
+  bytes.buffer.slice(bytes.byteOffset, bytes.byteOffset + bytes.length),
+);
+const local = { grid, design: "las" };
+
+/** 아무 화면 부품 — 무엇을 읽든 · 부르든 또 그것(DOM · 오버레이 · 도구줄 흉내). */
+function anyNode() {
+  const box = { dataset: {}, style: {}, classList: { add() {}, remove() {}, toggle() {} } };
+  return new Proxy(function node() {}, {
+    get: (_t, key) => {
+      if (key in box) return box[key];
+      if (key === "then" || typeof key === "symbol") return undefined;
+      return (box[key] = anyNode());
+    },
+    set: (_t, key, value) => ((box[key] = value), true),
+    apply: () => anyNode(),
+  });
+}
+const anyModule = (own = {}) =>
+  new Proxy(own, {
+    get: (t, key) =>
+      key in t
+        ? t[key]
+        : key === "__esModule"
+          ? true
+          : typeof key === "symbol"
+            ? undefined
+            : anyNode(),
+  });
+globalThis.document = anyNode();
+globalThis.HTMLElement = function HTMLElement() {};
+
+STUBS["B05_Profile_Api_Replan"] = {
+  analysisTerrain: () => "las",
+  fetchRoutePlan: async () => ({
+    planned: job.line,
+    curves: job.curves,
+    min_radius_m: job.minRadius,
+    station_snap: job.stationSnap,
+  }),
+};
+STUBS["B05_Profile_Api_Structures"] = anyModule({
+  fetchStructures: async () => ({ structures: job.structures }),
+  fetchStructureTypes: async () => job.types,
+  readPendingStructures: () => null,
+});
+STUBS["B05_Profile_Api_TerrainGrid"] = {
+  loadDesignTerrainGrid: async () => local,
+  groundStageDeps: () => ({ grid: () => local, remote: async () => [] }),
+};
+STUBS["B04_PreProcess_Api_Fetch"] = {
+  fetchDetailPipePoints: async () => ({
+    pipe_points: job.pipes.map((pipe) => ({ ...pipe, lonlat: [0, 0] })),
+  }),
+};
+STUBS["B06_Section_UI_Standard_Panel"] = { effectiveStandardCross: () => job.standard };
+// 구조물 초안 얹기(측점 계획 · 형상) — 이 시험 밖 · 아무 일 없음
+STUBS["B06_Section_Section_Drafts"] = {
+  withDraftStations: async () => undefined,
+  withDraftShapes: async () => undefined,
+  forgetDraftStations: () => undefined,
+};
+STUBS["B06_Section_Api_Fetch"] = {
+  fetchSectionDetail: async () => JSON.parse(JSON.stringify(job.detail)),
+  saveSections: async () => undefined,
+};
+// 횡단 다시 셈(브라우저 · B05 crossPreview · B06 카드 같은 창구) — 부른 횟수 · 면적은 서버와 달라짐(두 배)
+let refreshCalls = 0;
+const doubled = (detail) =>
+  detail.cross_sections.forEach((section) => {
+    if (!section.design) return;
+    const design = { ...section.design };
+    for (const [key, value] of Object.entries(design))
+      if (key.endsWith("_m2") && typeof value === "number") design[key] = value * 2;
+    section.design = design;
+  });
+STUBS["B06_Section_Cross_Refresh"] = {
+  refreshCrossDesigns: async ({ detail }) => {
+    refreshCalls += 1;
+    doubled(detail);
+    return detail.cross_sections.map((s) => s.chainage_m);
+  },
+  holdScreenAlignment: () => () => undefined,
+  USER_TOUCHED_KEYS: [],
+};
+// 그리기 — 진짜 `renderProfile` 의 낡음 판정 줄만(같은 함수 · 같은 인자) · SVG 는 안 그림
+const draws = [];
+let opened = null;
+STUBS["B05_Profile_UI_Profile_Render"] = {
+  renderProfile: (ctx) => {
+    const detail = ctx.detail();
+    if (!detail) return;
+    const alignment = ctx.alignment();
+    const longitudinal = detail.longitudinal;
+    const designProfiles = alignment
+      ? [profileData.toDesignProfile(alignment, longitudinal.design_profiles?.[0])]
+      : (longitudinal.design_profiles ?? []);
+    const key = common.staleKey({
+      longitudinal: { design_profiles: designProfiles },
+      cross_sections: detail.cross_sections,
+    });
+    draws.push({ key, saved: detail === opened });
+    ctx.onStaleDesigns?.(key);
+  },
+};
+STUBS["common_util_view_window"] = { frameOf: (_root, fn) => fn() };
+for (const name of [
+  "B05_Profile_UI_Profile_Balance",
+  "B05_Profile_UI_Profile_Heights",
+  "B05_Profile_UI_Profile_Panel_Tools",
+  "B05_Profile_UI_Profile_Zoom",
+  "B05_Profile_UI_Profile_Drag",
+  "B05_Profile_UI_Profile_MassHaul",
+  "design_profile_overlays",
+  "design_profile_viewport",
+  "design_save",
+  "B05_Profile_Api_Fetch",
+  "common_util_mass_haul_balance_view",
+])
+  STUBS[name] = anyModule();
+
+const pageMod = load("A00_Common", "design", "design_pipeline_page.ts");
+const storeMod = load("A00_Common", "design", "design_store.ts");
+const sectionStore = load("B06_Section", "B06_Section_Section_Store.ts");
+const common = load("B06_Section", "B06_Section_UI_Section_Common.ts");
+const profileData = load("B05_Profile", "logic", "B05_Profile_UI_Profile_Data.ts");
+const alignmentMod = load("B05_Profile", "logic", "B05_Profile_UI_Profile_Alignment.ts");
+const baseMod = load("A00_Common", "design", "design_profile_base.ts");
+const massHaul = load("common_util", "common_util_mass_haul.ts");
+const profileMod = load("A00_Common", "design", "design_profile.ts");
+
+const tick = (ms = 0) => new Promise((resolve) => setTimeout(resolve, ms));
+const runs = () => globalThis.__aisloPipeline?.runs ?? [];
+/** 묶음 · 상세 가게 · 다시 셈이 조용해질 때까지. */
+async function quiet() {
+  let seen = -1;
+  for (let i = 0; i < 400; i += 1) {
+    await tick(30);
+    const last = runs()[runs().length - 1];
+    const count = runs().length + refreshCalls * 1000 + draws.length * 1e6;
+    if (count === seen && (!last || last.outcome !== "running")) return;
+    seen = count;
+  }
+  throw new Error("묶음이 조용해지지 않음");
+}
+const n = job.nodes.length;
+const draftOf = (nodes) => ({
+  nodes,
+  curveOn: Array(n).fill(true),
+  curveRadius: Array(n).fill(null),
+  curveLock: Array(n).fill(null),
+  curveArc: Array(n).fill(null),
+  stationSnap: job.stationSnap,
+});
+const shift = (index, dx, dy) =>
+  job.nodes.map((node, i) => (i === index ? [node[0] + dx, node[1] + dy] : node));
+const sliceRuns = (mark) =>
+  runs()
+    .slice(mark)
+    .map((r) => ({
+      sources: r.sources,
+      outcome: r.outcome,
+      restored: r.restored ?? null,
+      why: r.restoreWhy ?? null,
+    }));
+const finalOf = (detail) => {
+  const [series] = massHaul.computeMassHaulSeries(
+    detail.longitudinal,
+    detail.cross_sections,
+    job.conversion,
+    undefined,
+    ["cross"],
+  );
+  const points = series?.result.points ?? [];
+  return points.length ? points[points.length - 1].cumulative_volume_m3 : null;
+};
+const crossOf = (detail) =>
+  JSON.stringify(detail.cross_sections.map((s) => [s.chainage_m, s.design, s.samples]));
+/** 서버 정본 흉내 — 저장 횡단 계획고 = 열 때 종단도 계획선(낡음 0 · 서버가 낸 상세와 같음). */
+function settleDesigns(detail) {
+  const pa = detail.longitudinal.profile_alignment;
+  const base = baseMod.listedBase(alignmentMod.toAlignmentBase(pa), detail, []);
+  const samples = alignmentMod.buildAlignment(base, pa.edits).samples;
+  const at = (c) => {
+    const i = samples.findIndex((s) => s.chainage_m >= c);
+    if (i < 0) return samples[samples.length - 1].elevation_m;
+    if (i === 0) return samples[0].elevation_m;
+    const a = samples[i - 1];
+    const b = samples[i];
+    return (
+      a.elevation_m +
+      ((b.elevation_m - a.elevation_m) * (c - a.chainage_m)) / (b.chainage_m - a.chainage_m)
+    );
+  };
+  detail.cross_sections.forEach((s) => (s.design.design_elevation_m = at(s.chainage_m)));
+}
+
+async function run() {
+  const P = "proj-349l";
+  const R = 7;
+  window.localStorage.setItem("frd_current_project_id", P);
+  opened = await sectionStore.loadSectionDetail(P, R);
+  settleDesigns(opened);
+  const profile = profileMod.createDesignProfile({
+    projectId: P,
+    view: "profile",
+    onSelectStation: () => undefined,
+  });
+  const live = () => sectionStore.loadSectionDetail(P, R);
+  pageMod.routeDraftBridge(P, profile, {
+    stationIntervalM: job.interval,
+    // `design_view_profile` 의 onDraftDropped 그대로
+    onDraftDropped: async (routeId, saved, stations) => {
+      const back = saved && (await sectionStore.restoreSectionDetail(P, routeId, saved, stations));
+      if (saved && !back) return "unchanged";
+      if (back?.same) return "saved";
+      await sectionStore.swapSectionStations(P, routeId, stations);
+      return saved ? "stations" : "no-saved";
+    },
+  });
+  // 종단 보기 `renderSections` · followSwap 그대로 — 새 상세 → render · 비정규 측점 · 가게 stations → 갈아끼움
+  const show = (detail) => {
+    profile.render(detail, job.interval, R);
+    profile.setIrregularStations([]);
+  };
+  const stopListen = sectionStore.subscribeSectionDetail(P, R, (next) => show(next));
+  const stopStore = storeMod.useDesignStore(P, null).subscribe("stations", (stations) => {
+    if (stations?.length) void sectionStore.swapSectionStations(P, R, stations);
+  });
+  show(opened);
+  profile.setEarthworkContext({ conversion: job.conversion });
+  await quiet();
+  const measure = async (mark, refreshMark) => {
+    const detail = await live();
+    return {
+      runs: sliceRuns(mark),
+      refresh: refreshCalls - refreshMark,
+      lastKey: draws[draws.length - 1]?.key ?? null,
+      drawnSaved: draws[draws.length - 1]?.saved ?? null,
+      sameObject: detail === opened,
+      stations: detail.cross_sections.map((s) => s.chainage_m),
+      final: finalOf(detail),
+      cross: crossOf(detail),
+      edits: JSON.stringify(profile.pipelineSource().edits),
+      pipeEdits: JSON.stringify(pageMod.pagePipeline(P).input("alignment")),
+    };
+  };
+  const open = await measure(0, 0);
+
+  // 노선 꼭짓점 한 번 끌기 — 상세가 새 노선 측점으로 갈아끼워짐 · 그 횡단을 카드가 다시 셈(흉내)
+  let mark = runs().length;
+  let refreshMark = refreshCalls;
+  const bridge = pageMod.routeDraftBridge(P, profile);
+  bridge.edited(draftOf(shift(1, 6, -4)));
+  await quiet();
+  doubled(await live());
+  const drag = await measure(mark, refreshMark);
+
+  // 되돌리기 한 번(초안 버림)
+  mark = runs().length;
+  refreshMark = refreshCalls;
+  bridge.edited(null);
+  await quiet();
+  const undo = await measure(mark, refreshMark);
+
+  // 횡단 보기(B06) 다녀옴 — 종단도는 횡단 보기 자리에서 `shownDetail`(묶음 새 상세 없으면 저장 상세)을 그림
+  mark = runs().length;
+  refreshMark = refreshCalls;
+  profile.setView("cross");
+  show(pageMod.pipelineDetail(P) ?? (await live()));
+  profile.setEarthworkContext({ conversion: job.conversion });
+  await quiet();
+  profile.setView("profile");
+  profile.setActive(true);
+  await quiet();
+  const back = await measure(mark, refreshMark);
+  const blocked = pageMod.pagePipeline(P).blockedWrites;
+  stopListen();
+  stopStore();
+  pageMod.disposePagePipeline(P);
+  return { open, drag, undo, back, blocked };
+}
+
+run()
+  .then((out) => {
+    process.stdout.write(JSON.stringify(out));
+    process.exit(0);
+  })
+  .catch((error) => {
+    process.stderr.write(String(error && error.stack ? error.stack : error));
+    process.exit(1);
+  });
diff --git a/resources/tester/test_346_2_pipeline_cross_page.py b/resources/tester/test_346_2_pipeline_cross_page.py
index 0673e0347..b6645a1e6 100644
--- a/resources/tester/test_346_2_pipeline_cross_page.py
+++ b/resources/tester/test_346_2_pipeline_cross_page.py
@@ -3,7 +3,7 @@
 · 열 때 한 번(저장 노선 · 발자국 · 저장 횡단 입력이 측점 열쇠로 모임)
   초안 없으면 3D 낡음 · 흙 배분 안 함
 · 노선 점 옮김 한 번에 cross · footprint · masshaul 까지 · 단계 합 0.3 s 안
-· 누가토량 = 서버 엔진(generate_sections · compute_cross_design)으로
+· 누가토량 = 서버 엔진(generate_sections · compute_cross_design · 미교차 넓힘 extend_unclosed)으로
   같은 노선을 셈한 값과 같은 자리수
 · 상단측(단면 유형 기본값) = 서버 `uphill_side` 짝(거울)
 · 늦은 응답 버림(흙 배분 끊김 · 옛 차례 haul 안 들어옴)
@@ -38,6 +38,7 @@ from B05_Profile.B05_Profile_Engine_Grade_Profile import (  # noqa: E402
 )
 from B05_Profile.B05_Profile_Structures_Schema import structure_type_map  # noqa: E402
 from B06_Section.B06_Section_Engine_Design import compute_cross_design  # noqa: E402
+from B06_Section.B06_Section_Engine_SampleExtend import extend_unclosed  # noqa: E402
 from common_util.common_util_drainage_pipes import parse_pipe_points  # noqa: E402
 from common_util.common_util_route_polyline import build_planned_polyline  # noqa: E402
 from common_util.common_util_structure_station import plan_stations  # noqa: E402
@@ -183,10 +184,12 @@ def _run(case) -> dict:
                 "planRadius": s.get("plan_radius_m"),
                 "outer": s.get("curve_outer_side"),
                 "widening": s.get("curve_widening_m"),
+                "frame": s["frame"],
             }
             for s in server["cross_sections"]
         ]
         out["pipes"] = pipes
+        out["sampler"] = sampler
     return out
 
 
@@ -239,15 +242,23 @@ def test_누가토량_서버_엔진과_같은_자리수(r):
     nets = []
     for a, b in zip(ts, py):
         assert abs(a["chainage"] - b["chainage"]) < 1e-3
-        design = compute_cross_design(
-            b["samples"],
-            a["elevation"],
-            ground_type="ripping_rock",
-            section_mode=f"{b['uphill'] or 'left'}_cut",
-            plan_radius_m=b["planRadius"],
-            curve_outer_side=b["outer"],
-            curve_widening_m=b["widening"],
-        )
+
+        def compute(samples, a=a, b=b):
+            return compute_cross_design(
+                samples,
+                a["elevation"],
+                ground_type="ripping_rock",
+                section_mode=f"{b['uphill'] or 'left'}_cut",
+                plan_radius_m=b["planRadius"],
+                curve_outer_side=b["outer"],
+                curve_widening_m=b["widening"],
+            )
+
+        design = compute(b["samples"])
+        # 미교차 넓힘 — 묶음 cross 도 같은 지형 격자로 넓힘(349-0j · [저장] 정본 길)
+        wide = extend_unclosed(b["samples"], b["frame"], compute, r["sampler"])
+        if wide is not None and (wide[1]["left_m"] or wide[1]["right_m"]):
+            design = compute(wide[0])
         assert abs(design["cut_area_m2"] - a["cut"]) < 0.05 + 0.01 * design["cut_area_m2"]
         assert abs(design["fill_area_m2"] - a["fill"]) < 0.05 + 0.01 * design["fill_area_m2"]
         nets.append((b["chainage"], design["cut_area_m2"] - design["fill_area_m2"]))
diff --git a/resources/tester/test_349_0l_undo_draw.py b/resources/tester/test_349_0l_undo_draw.py
new file mode 100644
index 000000000..37000bc56
--- /dev/null
+++ b/resources/tester/test_349_0l_undo_draw.py
@@ -0,0 +1,151 @@
+"""PLAN 349-0l sub7 — 되돌리면 종단도 · 상세 · 측점이 열 때와 한 벌(다시 셈 0).
+
+· 열기 → 노선 꼭짓점 끌기 → 되돌리기 → 횡단 보기 → 종단 보기 — 누가토량 · 측점 · 횡단 = 열기 값
+· 진짜 종단도 낡음 판정 · crossPreview 예약을 거침 — 되돌린 뒤 다시 셈 0 · 낡음 0
+· 묶음 기록에 되돌림 길(restored · 까닭) · 되돌리기 = 묶음 한 번
+짝: `helper_349_0l_undo_draw.cjs`(실제 TS 를 Node 로 · 화면 부품 · 서버 창구만 가짜).
+"""
+
+from __future__ import annotations
+
+import csv
+import json
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+import pytest
+
+HERE = Path(__file__).resolve().parent
+ROOT = HERE.parents[1]
+if str(ROOT) not in sys.path:
+    sys.path.insert(0, str(ROOT))
+
+from B05_Profile.B05_Profile_Structures_Schema import structure_type_map  # noqa: E402
+from common_util.common_util_surface_sampler import dtm_grid_bytes  # noqa: E402
+from config.config_system_design import STANDARD_CROSS_SECTION  # noqa: E402
+
+pytestmark = pytest.mark.skipif(
+    not (ROOT / "config" / "node_modules" / "typescript").is_dir(),
+    reason="프론트엔드 의존성 미설치",
+)
+
+PROJECT = ROOT / "storage/1/3/6d3b2812-6d5a-4168-a932-40e4ae303d5a"  # 검증_sub7
+ROUTE = PROJECT / "B05_Profile/route"
+SECTION = PROJECT / "B06_Section"
+GRID = PROJECT / "B04_PreProcess/models/dtm_classification_smooth.npz"
+ONES = {g: {"loose": 1.0, "compacted": 1.0} for g in ("soil", "ripping_rock", "blasting_rock")}
+
+
+def _csv(path: Path) -> list[list[float]]:
+    with path.open(encoding="utf-8") as handle:
+        return [[float(r["x"]), float(r["y"])] for r in csv.DictReader(handle)]
+
+
+def _json(path: Path):
+    return json.loads(path.read_text(encoding="utf-8"))
+
+
+@pytest.fixture(scope="module")
+def r() -> dict:
+    if not (GRID.is_file() and (SECTION / "longitudinal/longitudinal.json").is_file()):
+        pytest.skip("검증_sub7 없음")
+    curves = _json(ROUTE / "planned_route_curves.json")
+    sections = sorted(
+        (_json(p) for p in (SECTION / "cross_sections").glob("cross_*.json")),
+        key=lambda s: s["chainage_m"],
+    )
+    pipes = _json(PROJECT / "B04_PreProcess/drainage/edits/pipe_points.json")["points"]
+    # 저장 횡단 면적 = 서버가 상세를 낼 때 셈(파일엔 없음) — 정본 대신 정한 값
+    for i, section in enumerate(sections):
+        section["design"] = {
+            "ground_type": "soil",
+            "design_elevation_m": section["center_z"],
+            "cut_area_m2": 4.0 + (i % 5),
+            "fill_area_m2": 1.5 + (i % 3),
+        }
+    job = {
+        "line": _csv(ROUTE / "planned_route.csv"),
+        "nodes": _csv(ROUTE / "planned_route_nodes.csv"),
+        "curves": [
+            {k: c[k] for k in ("start", "apex", "end", "radius_m")} for c in curves["curves"]
+        ],
+        "stationSnap": bool(curves.get("station_snap")),
+        "minRadius": curves["min_radius_m"],
+        "interval": 20.0,
+        "types": [
+            {"type_id": t.type_id, "group": t.group, "placement": t.placement}
+            for t in structure_type_map().values()
+        ],
+        "pipes": pipes,
+        "standard": STANDARD_CROSS_SECTION,
+        "conversion": ONES,
+        # 구조물 하나 — 첫 관 자리(같은 측점을 덮음 · 측점 목록 그대로) · follow 가 함께 옮김
+        "structures": [
+            {
+                "structure_id": "s-349l",
+                "type_id": "cross_drain_exposed",
+                "chainage_m": pipes[0]["chainage_m"],
+                "x": pipes[0]["x"],
+                "y": pipes[0]["y"],
+            }
+        ],
+        "detail": {
+            "longitudinal": _json(SECTION / "longitudinal/longitudinal.json"),
+            "cross_sections": sections,
+        },
+    }
+    with tempfile.TemporaryDirectory() as folder:
+        path = Path(folder) / "job.json"
+        path.write_text(json.dumps(job), encoding="utf-8")
+        grid = Path(folder) / "grid.bin"
+        grid.write_bytes(dtm_grid_bytes(GRID))
+        proc = subprocess.run(  # noqa: S603 — 고정 실행 파일
+            ["node", str(HERE / "helper_349_0l_undo_draw.cjs"), str(path), str(grid)],
+            capture_output=True,
+            text=True,
+            encoding="utf-8",
+            timeout=300,
+        )
+    assert proc.returncode == 0, proc.stderr
+    return json.loads(proc.stdout)
+
+
+def test_열기_낡음_0_다시_셈_0(r):
+    o = r["open"]
+    assert [x["outcome"] for x in o["runs"]] == ["done"], o["runs"]
+    assert o["lastKey"] == "" and o["drawnSaved"]
+    assert o["refresh"] == 0
+    assert o["sameObject"] and o["final"] is not None
+
+
+def test_끌기_새_측점(r):
+    d = r["drag"]
+    assert [x["sources"] for x in d["runs"]] == [["route"]], d["runs"]
+    assert not d["sameObject"]  # 시험이 갈아끼움 길을 실제로 거침
+    assert d["final"] != r["open"]["final"]
+
+
+def test_되돌리기_열기_값_다시_셈_0(r):
+    u, o = r["undo"], r["open"]
+    assert [(x["sources"], x["restored"], x["why"]) for x in u["runs"]] == [
+        (["route"], True, "saved")
+    ], u["runs"]
+    assert u["refresh"] == 0
+    assert u["lastKey"] == "" and u["drawnSaved"]
+    assert u["sameObject"]
+    assert u["stations"] == o["stations"]
+    assert u["cross"] == o["cross"]
+    assert u["final"] == o["final"]
+    assert u["edits"] == o["edits"] and u["pipeEdits"] == u["edits"]
+
+
+def test_횡단_보기_다녀와도_같은_값(r):
+    b, o = r["back"], r["open"]
+    assert b["runs"] == [], b["runs"]
+    assert b["refresh"] == 0
+    assert b["lastKey"] == "" and b["drawnSaved"]
+    assert b["final"] == o["final"]
+    assert b["cross"] == o["cross"]
+    assert r["blocked"] == 0