diff --git a/internal/web/static/css/openfsd/airport-editor.css b/internal/web/static/css/openfsd/airport-editor.css
index 5bc5ed5..5fd05ef 100644
--- a/internal/web/static/css/openfsd/airport-editor.css
+++ b/internal/web/static/css/openfsd/airport-editor.css
@@ -253,17 +253,32 @@
   cursor: default;
 }
 
-/* Vertex drag handles (Leaflet divIcon) */
+/* Vertex drag handles (Leaflet divIcon).
+ * Width/height MUST match VERTEX_HANDLE_PX (map-layers.js) — keep in sync.
+ * Do not use negative margin; Leaflet positions via iconAnchor. */
 .apted-vertex-handle {
-  width: 12px !important;
-  height: 12px !important;
-  margin-left: -6px !important;
-  margin-top: -6px !important;
+  position: relative; /* containing block for ::after hit pad */
+  overflow: visible;  /* do not clip expanded hit area */
+  width: 16px !important;
+  height: 16px !important;
+  margin: 0 !important; /* positioning is iconAnchor only */
   border: 2px solid #4a7ab0;
   border-radius: 50%;
   background: #fff;
   box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.25);
-  cursor: move;
+  cursor: grab;
+  box-sizing: border-box;
+}
+.apted-vertex-handle:active {
+  cursor: grabbing;
+  background: #e8f0fa;
+}
+/* Expanded hit area without growing the visible disc.
+ * Relies on position:relative + overflow:visible on the icon. */
+.apted-vertex-handle::after {
+  content: '';
+  position: absolute;
+  inset: -6px; /* ~28px effective target */
 }
 
 /* Inspector form density */
diff --git a/internal/web/static/js/openfsd/airport-editor/main.js b/internal/web/static/js/openfsd/airport-editor/main.js
index 1dbbc9f..e02f17d 100644
--- a/internal/web/static/js/openfsd/airport-editor/main.js
+++ b/internal/web/static/js/openfsd/airport-editor/main.js
@@ -114,12 +114,12 @@ function main() {
     },
     onVertexDrag(si, vi, lat, lon) {
       setVertex(doc, si, vi, { lat, lon });
-      // Live-update surface polyline without full refresh of handles mid-drag.
-      // Full refresh on dragend.
+      // Intentionally no refresh — OverlayController live-updates the surface layer.
+      // Hard invariant: never refresh/render while OverlayController._dragging.
     },
     onVertexDragEnd(si, vi, lat, lon) {
       setVertex(doc, si, vi, { lat, lon });
-      afterAptMutation();
+      afterAptMutation({ fit: false }); // full refresh — _dragging already false
     },
     onAircraftDrag(index, lat, lon) {
       updateAircraft(doc, index, { lat, lon });
diff --git a/internal/web/static/js/openfsd/airport-editor/map-layers.js b/internal/web/static/js/openfsd/airport-editor/map-layers.js
index 370a87d..f8f574e 100644
--- a/internal/web/static/js/openfsd/airport-editor/map-layers.js
+++ b/internal/web/static/js/openfsd/airport-editor/map-layers.js
@@ -202,6 +202,111 @@ export function escapeHtml(s) {
     .replace(/'/g, ''');
 }
 
+/** Keep in sync with .apted-vertex-handle width/height in airport-editor.css */
+export const VERTEX_HANDLE_PX = 16;
+
+/** Duration after dragend during which map clicks are ignored. */
+export const MAP_CLICK_SUPPRESS_MS = 250;
+
+/**
+ * Pure: options for the vertex L.marker (no Leaflet instance required).
+ * Icon is constructed at the call site with L.divIcon({...buildVertexHandleIconOptions()}).
+ * @param {number} vertexIndex
+ * @returns {object}
+ */
+export function buildVertexHandleOptions(vertexIndex) {
+  return {
+    draggable: true,
+    autoPan: false,
+    keyboard: false,
+    zIndexOffset: 2000,
+    bubblingMouseEvents: false,
+    title: `Vertex ${vertexIndex + 1}`,
+  };
+}
+
+/**
+ * Pure icon size/anchor for divIcon — symmetry asserted in unit tests.
+ * @returns {{ className: string, iconSize: [number, number], iconAnchor: [number, number] }}
+ */
+export function buildVertexHandleIconOptions() {
+  const px = VERTEX_HANDLE_PX;
+  return {
+    className: 'apted-vertex-handle leaflet-interactive',
+    iconSize: [px, px],
+    iconAnchor: [px / 2, px / 2],
+  };
+}
+
+/**
+ * Pure: points → Leaflet latlng tuples (finite only).
+ * @param {{lat:number,lon:number}[]} points
+ * @returns {Array<[number, number]>}
+ */
+export function pointsToLatLngs(points) {
+  const out = [];
+  if (!Array.isArray(points)) return out;
+  for (const p of points) {
+    if (Number.isFinite(p?.lat) && Number.isFinite(p?.lon)) {
+      out.push([p.lat, p.lon]);
+    }
+  }
+  return out;
+}
+
+/**
+ * Pure: apply latlngs to a surface layer duck-typed like Leaflet polyline/circleMarker.
+ * Prefer setLatLngs (polyline) then setLatLng (circleMarker). No-op if neither.
+ * @param {{ setLatLngs?: Function, setLatLng?: Function }|null|undefined} layer
+ * @param {Array<[number, number]>} latlngs
+ * @returns {'polyline'|'point'|'none'}
+ */
+export function applySurfaceLatLngs(layer, latlngs) {
+  if (!layer || !latlngs || latlngs.length === 0) return 'none';
+  if (typeof layer.setLatLngs === 'function') {
+    layer.setLatLngs(latlngs);
+    return 'polyline';
+  }
+  if (typeof layer.setLatLng === 'function') {
+    layer.setLatLng(latlngs[0]);
+    return 'point';
+  }
+  return 'none';
+}
+
+/**
+ * Pure: patch one vertex in a points array (immutable-style new array).
+ * @param {{lat:number,lon:number}[]} points
+ * @param {number} vertexIndex
+ * @param {number} lat
+ * @param {number} lon
+ * @returns {{lat:number,lon:number}[]}
+ */
+export function patchVertexPoints(points, vertexIndex, lat, lon) {
+  const src = Array.isArray(points) ? points : [];
+  return src.map((p, i) =>
+    i === vertexIndex ? { lat, lon } : { lat: p.lat, lon: p.lon },
+  );
+}
+
+/**
+ * Pure: whether a map click should be ignored (active drag or post-drag suppress window).
+ * Post-drag suppress does NOT block full render — only map click handlers use this.
+ * @param {{ dragging: boolean, dragEndedAt: number, suppressMs: number }} state
+ * @param {number} [now]
+ * @returns {boolean}
+ */
+export function shouldSuppressMapClick(state, now = Date.now()) {
+  if (state.dragging) return true;
+  if (
+    state.dragEndedAt > 0 &&
+    now - state.dragEndedAt < state.suppressMs
+  ) {
+    return true;
+  }
+  return false;
+}
+
 /**
  * Build a Leaflet tooltip content node with textContent only (never innerHTML).
  * Leaflet 1.9 uses innerHTML for string content — always pass an Element.
@@ -381,8 +486,10 @@ export class OverlayController {
     this._airport = null;
     /** @type {import('./model.js').Aircraft[]} */
     this._aircraft = [];
-    /** @type {boolean} */
+    /** @type {boolean} true only while a vertex/aircraft pointer drag is active */
     this._dragging = false;
+    /** @type {number} ms timestamp of last dragend (0 = never / reset on dragstart) */
+    this._dragEndedAt = 0;
     this._planeIcon = L.icon({
       iconUrl: this.planeIconUrl,
       iconSize: [16, 16],
@@ -391,7 +498,18 @@ export class OverlayController {
 
     if (this.onMapClick) {
       map.on('click', (ev) => {
-        if (this._dragging) return;
+        if (
+          shouldSuppressMapClick(
+            {
+              dragging: this._dragging,
+              dragEndedAt: this._dragEndedAt,
+              suppressMs: MAP_CLICK_SUPPRESS_MS,
+            },
+            Date.now(),
+          )
+        ) {
+          return;
+        }
         const ll = ev.latlng;
         this.onMapClick(ll.lat, ll.lng, ev.originalEvent);
       });
@@ -547,8 +665,21 @@ export class OverlayController {
     this._layerByKey.set(key, layer);
   }
 
+  /**
+   * Live-update the surface layer for surfaceIndex from points (no full render).
+   * Layer under surface:N is polyline (setLatLngs) or circleMarker (setLatLng).
+   * @param {number} surfaceIndex
+   * @param {{lat:number,lon:number}[]} points
+   */
+  _liveSetSurfacePoints(surfaceIndex, points) {
+    const layer = this._layerByKey.get(`surface:${surfaceIndex}`);
+    applySurfaceLatLngs(layer, pointsToLatLngs(points));
+  }
+
   /**
    * Draggable vertex handles for selected surface.
+   * Single divIcon marker per vertex (no companion circleMarker).
+   * Normative drag state machine: paint first, clear _dragging before onVertexDragEnd.
    * @param {import('./model.js').Surface} surface
    * @param {number} surfaceIndex
    */
@@ -558,44 +689,36 @@ export class OverlayController {
     for (let vi = 0; vi < pts.length; vi++) {
       const p = pts[vi];
       if (!Number.isFinite(p.lat) || !Number.isFinite(p.lon)) continue;
-      const marker = L.circleMarker([p.lat, p.lon], {
-        radius: 6,
-        color: '#4a7ab0',
-        weight: 2,
-        fillColor: '#fff',
-        fillOpacity: 1,
-        opacity: 1,
-      });
-      // Use drag via map events on mousedown — circleMarker is not draggable by default.
-      // Prefer Leaflet.Marker with divIcon for drag support when available.
       const handle = L.marker([p.lat, p.lon], {
-        draggable: true,
-        zIndexOffset: 2000,
-        icon: L.divIcon({
-          className: 'apted-vertex-handle',
-          iconSize: [12, 12],
-          iconAnchor: [6, 6],
-        }),
-        title: `Vertex ${vi + 1}`,
+        ...buildVertexHandleOptions(vi),
+        icon: L.divIcon(buildVertexHandleIconOptions()),
       });
-      handle.on('dragstart', () => {
+      handle.on('dragstart', (ev) => {
         this._dragging = true;
+        this._dragEndedAt = 0;
+        if (ev?.originalEvent) L.DomEvent.stopPropagation(ev.originalEvent);
       });
       handle.on('drag', (ev) => {
         const ll = ev.target.getLatLng();
+        // 1) Overlay-local paint FIRST (order-independent of model callback).
+        const base = this._airport?.surfaces?.[surfaceIndex]?.points || [];
+        const next = patchVertexPoints(base, vi, ll.lat, ll.lng);
+        this._liveSetSurfacePoints(surfaceIndex, next);
+        // 2) Model commit path (main must not refresh).
         this.onVertexDrag(surfaceIndex, vi, ll.lat, ll.lng);
       });
       handle.on('dragend', (ev) => {
         const ll = ev.target.getLatLng();
+        // Final live paint (covers last frame).
+        const base = this._airport?.surfaces?.[surfaceIndex]?.points || [];
+        const next = patchVertexPoints(base, vi, ll.lat, ll.lng);
+        this._liveSetSurfacePoints(surfaceIndex, next);
+        // State machine: clear pointer-down flag BEFORE app refresh path.
+        this._dragEndedAt = Date.now();
+        this._dragging = false;
         this.onVertexDragEnd(surfaceIndex, vi, ll.lat, ll.lng);
-        // Small delay so map click from drag end is ignored.
-        setTimeout(() => {
-          this._dragging = false;
-        }, 50);
       });
       handle.addTo(this.vertexGroup);
-      // Keep circle under for visibility if divIcon fails in tests.
-      marker.addTo(this.vertexGroup);
     }
   }
 
@@ -627,8 +750,10 @@ export class OverlayController {
       this.onSelect({ type: 'aircraft', index });
     });
     if (this.editable) {
-      marker.on('dragstart', () => {
+      marker.on('dragstart', (ev) => {
         this._dragging = true;
+        this._dragEndedAt = 0;
+        if (ev?.originalEvent) L.DomEvent.stopPropagation(ev.originalEvent);
       });
       marker.on('drag', (ev) => {
         const ll = ev.target.getLatLng();
@@ -636,10 +761,10 @@ export class OverlayController {
       });
       marker.on('dragend', (ev) => {
         const ll = ev.target.getLatLng();
+        // Same state machine as vertex: clear _dragging before callback so full refresh runs.
+        this._dragEndedAt = Date.now();
+        this._dragging = false;
         this.onAircraftDragEnd(index, ll.lat, ll.lng);
-        setTimeout(() => {
-          this._dragging = false;
-        }, 50);
       });
     }
     marker.addTo(this.group);
diff --git a/webjs/airport-editor/map-layers.test.js b/webjs/airport-editor/map-layers.test.js
index 10d12ec..cdf7b18 100644
--- a/webjs/airport-editor/map-layers.test.js
+++ b/webjs/airport-editor/map-layers.test.js
@@ -1,6 +1,14 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
 
+/**
+ * Pure OverlayController helpers.
+ *
+ * RC1 live path = applySurfaceLatLngs (polyline setLatLngs / point setLatLng).
+ * RC2 no companion circle factory in exports — single divIcon via builders.
+ * RC3 no CSS margin in JS positioning — iconSize/iconAnchor only.
+ * K5 suppress ≠ block render: dragging:false + within suppressMs still allows full render by contract.
+ */
 import {
   surfaceStyle,
   collectLatLngs,
@@ -14,6 +22,14 @@ import {
   OSM_ATTRIBUTION,
   ESRI_TILE_URL,
   ESRI_ATTRIBUTION,
+  VERTEX_HANDLE_PX,
+  MAP_CLICK_SUPPRESS_MS,
+  buildVertexHandleOptions,
+  buildVertexHandleIconOptions,
+  pointsToLatLngs,
+  applySurfaceLatLngs,
+  patchVertexPoints,
+  shouldSuppressMapClick,
 } from '../../internal/web/static/js/openfsd/airport-editor/map-layers.js';
 import {
   createEmptyDocument,
@@ -173,3 +189,139 @@ test('escapeHtml neutralizes markup in freeform AIR-like strings', () => {
   // Surface-style label still escapes if ever routed through HTML
   assert.equal(escapeHtml('G1 (park)'), 'G1 (park)');
 });
+
+test('pointsToLatLngs: empty, skips non-finite, preserves order', () => {
+  assert.deepEqual(pointsToLatLngs(null), []);
+  assert.deepEqual(pointsToLatLngs(undefined), []);
+  assert.deepEqual(pointsToLatLngs([]), []);
+  assert.deepEqual(
+    pointsToLatLngs([
+      { lat: 1, lon: 2 },
+      { lat: NaN, lon: 3 },
+      { lat: 4, lon: Infinity },
+      { lat: 5, lon: 6 },
+    ]),
+    [
+      [1, 2],
+      [5, 6],
+    ],
+  );
+});
+
+test('applySurfaceLatLngs: polyline, point, none branches', () => {
+  const polyCalls = [];
+  const poly = {
+    setLatLngs(ll) {
+      polyCalls.push(ll);
+    },
+  };
+  const latlngs = [
+    [10, 20],
+    [11, 21],
+  ];
+  assert.equal(applySurfaceLatLngs(poly, latlngs), 'polyline');
+  assert.deepEqual(polyCalls, [latlngs]);
+
+  const pointCalls = [];
+  const point = {
+    setLatLng(ll) {
+      pointCalls.push(ll);
+    },
+  };
+  assert.equal(applySurfaceLatLngs(point, latlngs), 'point');
+  assert.deepEqual(pointCalls, [[10, 20]]);
+
+  assert.equal(applySurfaceLatLngs({}, latlngs), 'none');
+  assert.equal(applySurfaceLatLngs(null, latlngs), 'none');
+  assert.equal(applySurfaceLatLngs(poly, []), 'none');
+  assert.equal(applySurfaceLatLngs(poly, null), 'none');
+});
+
+test('patchVertexPoints: replaces only index vi; does not mutate input', () => {
+  const src = [
+    { lat: 1, lon: 2 },
+    { lat: 3, lon: 4 },
+    { lat: 5, lon: 6 },
+  ];
+  const next = patchVertexPoints(src, 1, 30, 40);
+  assert.deepEqual(next, [
+    { lat: 1, lon: 2 },
+    { lat: 30, lon: 40 },
+    { lat: 5, lon: 6 },
+  ]);
+  // Input not mutated
+  assert.deepEqual(src[1], { lat: 3, lon: 4 });
+  assert.deepEqual(patchVertexPoints(null, 0, 1, 2), []);
+  assert.deepEqual(patchVertexPoints([], 0, 1, 2), []);
+});
+
+test('shouldSuppressMapClick matrix (K5: suppress ≠ block render)', () => {
+  const ms = MAP_CLICK_SUPPRESS_MS;
+  assert.equal(ms, 250);
+
+  // dragging true → suppress (render still forbidden by caller invariant while pointer down)
+  assert.equal(
+    shouldSuppressMapClick({ dragging: true, dragEndedAt: 0, suppressMs: ms }, 1000),
+    true,
+  );
+  assert.equal(
+    shouldSuppressMapClick(
+      { dragging: true, dragEndedAt: 900, suppressMs: ms },
+      1000,
+    ),
+    true,
+  );
+
+  // dragging false + within suppressMs after dragEndedAt → suppress click
+  // (full render is still allowed by contract — separate from this helper)
+  assert.equal(
+    shouldSuppressMapClick(
+      { dragging: false, dragEndedAt: 1000, suppressMs: ms },
+      1000 + ms - 1,
+    ),
+    true,
+  );
+
+  // dragging false + after suppress window → do not suppress
+  assert.equal(
+    shouldSuppressMapClick(
+      { dragging: false, dragEndedAt: 1000, suppressMs: ms },
+      1000 + ms,
+    ),
+    false,
+  );
+  assert.equal(
+    shouldSuppressMapClick(
+      { dragging: false, dragEndedAt: 1000, suppressMs: ms },
+      1000 + ms + 50,
+    ),
+    false,
+  );
+
+  // dragEndedAt 0 → never suppress when not dragging
+  assert.equal(
+    shouldSuppressMapClick({ dragging: false, dragEndedAt: 0, suppressMs: ms }, 5000),
+    false,
+  );
+});
+
+test('buildVertexHandleIconOptions: iconSize/iconAnchor symmetry', () => {
+  const icon = buildVertexHandleIconOptions();
+  assert.equal(VERTEX_HANDLE_PX, 16);
+  assert.equal(icon.iconSize[0], VERTEX_HANDLE_PX);
+  assert.equal(icon.iconSize[1], VERTEX_HANDLE_PX);
+  assert.equal(icon.iconAnchor[0], VERTEX_HANDLE_PX / 2);
+  assert.equal(icon.iconAnchor[1], VERTEX_HANDLE_PX / 2);
+  assert.match(icon.className, /apted-vertex-handle/);
+  assert.match(icon.className, /leaflet-interactive/);
+});
+
+test('buildVertexHandleOptions: draggable, autoPan, bubblingMouseEvents', () => {
+  const opts = buildVertexHandleOptions(2);
+  assert.equal(opts.draggable, true);
+  assert.equal(opts.autoPan, false);
+  assert.equal(opts.keyboard, false);
+  assert.equal(opts.bubblingMouseEvents, false);
+  assert.equal(opts.zIndexOffset, 2000);
+  assert.equal(opts.title, 'Vertex 3');
+});