diff --git a/internal/check-pinned-umd.mjs b/internal/check-pinned-umd.mjs
new file mode 100644
index 000000000..eb5dd9c06
--- /dev/null
+++ b/internal/check-pinned-umd.mjs
@@ -0,0 +1,50 @@
+#!/usr/bin/env node
+/**
+ * check-pinned-umd — library/utils/loadPinnedUmd.js loads a pinned UMD library WITHOUT touching the host
+ * page's global of the same name, and sets integrity + crossorigin. Headless: a stand-in document whose
+ * <script> "executes" a d3-style UMD body (`(t = globalThis).d3 = t.d3 || {}; t.d3.x = …`).
+ * CASES  host has no d3 · host owns an object d3 (must gain NO keys) · host has a non-configurable var d3
+ *        · a failed load rejects and leaves the host's d3 as it was · the tag carries the pinned SRI.
+ * EXIT 0 pass · 1 fail
+ */
+let bad = 0
+const check = (name, ok, got) => { if (!ok) bad++; console.log(`  ${ok ? 'ok  ' : 'FAIL'}  ${name}${ok ? '' : ' — ' + JSON.stringify(got)}`) }
+const PIN = { url: 'https://cdn.example/d3.min.js', integrity: 'sha384-TEST' }
+let fail = false, lastTag = null
+function page() {
+  const doc = { currentScript: null, head: { appendChild(s) {
+    lastTag = s
+    setTimeout(() => {
+      if (fail) return s.onerror && s.onerror()
+      doc.currentScript = s
+      const t = globalThis; t.d3 = t.d3 || {}; t.d3.version = '7.9.0'; t.d3.select = () => 'ours'   // the UMD body
+      doc.currentScript = null
+      s.onload && s.onload()
+    }, 0)
+  } }, createElement: () => ({}) }
+  globalThis.window = globalThis
+  globalThis.document = doc
+}
+const fresh = async () => (await import(`../library/utils/loadPinnedUmd.js?${Math.random()}`)).loadPinnedUmd
+
+page(); delete globalThis.d3
+let lib = await (await fresh())(PIN, 'd3')
+check('no host d3: returns the library', lib && lib.select() === 'ours', lib)
+check('no host d3: leaves no d3 on the page', globalThis.d3 === undefined, globalThis.d3)
+check('the tag carries integrity + crossorigin', lastTag.integrity === PIN.integrity && lastTag.crossOrigin === 'anonymous', lastTag)
+
+page(); const host = { version: '6.0.0', mine: true }; globalThis.d3 = host
+lib = await (await fresh())(PIN, 'd3')
+check('host owns a d3: gets our library', lib && lib.version === '7.9.0', lib)
+check('host owns a d3: its object gained NO keys', Object.keys(host).join() === 'version,mine' && host.version === '6.0.0', host)
+check('host owns a d3: window.d3 is still the host\'s', globalThis.d3 === host, globalThis.d3)
+
+page(); delete globalThis.d3; fail = true; globalThis.d3 = host
+let rejected = false
+try { await (await fresh())(PIN, 'd3') } catch { rejected = true }
+check('failed load rejects', rejected, rejected)
+check('failed load leaves the host d3 in place', globalThis.d3 === host, globalThis.d3)
+fail = false
+
+if (bad) { console.log(`PINNED-UMD: FAIL — ${bad} case(s).`); process.exit(1) }
+console.log("PINNED-UMD: PASS — a pinned UMD loads with SRI and never touches the host page's global.")
diff --git a/library/utils/loadPinnedUmd.js b/library/utils/loadPinnedUmd.js
new file mode 100644
index 000000000..5fac9cf0a
--- /dev/null
+++ b/library/utils/loadPinnedUmd.js
@@ -0,0 +1,62 @@
+/**
+ * loadPinnedUmd — load a PINNED, integrity-checked UMD library and capture it WITHOUT touching the host
+ * page's global of the same name. One copy of what pplr-data-maps (60faff1a) and the Wall carried twice.
+ *
+ * WHY THE TRAP (measured by rega on PPLR): a UMD build such as d3's writes its exports INTO an existing
+ * global — `(t = globalThis).d3 = t.d3 || {}` — so a host that owns a d3 had ours written over it (577
+ * added keys, version '7.9.0' on the host's object) even though we "put it back" afterwards. So while OUR
+ * script executes (document.currentScript === the tag), `window[globalName]` reads and writes a private
+ * slot; any other code, at every moment, reads and writes the host's own value. A non-configurable
+ * `var` global cannot be trapped: it is emptied for the load and restored after.
+ *
+ * @param {{url: string, integrity: string}} pin  an entry of library/constants/cdn.js
+ * @param {string} globalName  the name the UMD assigns (e.g. 'd3')
+ * @returns {Promise<any>} the library, cached per url; rejects on network/integrity failure
+ */
+const cache = new Map()
+
+export function loadPinnedUmd(pin, globalName) {
+  if (typeof window === 'undefined' || typeof document === 'undefined') return Promise.reject(new Error('no window'))
+  if (cache.has(pin.url)) return cache.get(pin.url)
+  const p = new Promise((resolve, reject) => {
+    const s = document.createElement('script')
+    s.src = pin.url
+    s.integrity = pin.integrity
+    s.crossOrigin = 'anonymous'
+    const own = Object.getOwnPropertyDescriptor(window, globalName)
+    let hostValue = window[globalName]
+    let ours
+    let trapped = false
+    if (!own || (own.configurable && 'value' in own)) {
+      Object.defineProperty(window, globalName, {
+        configurable: true, enumerable: own ? own.enumerable : true,
+        get: () => (document.currentScript === s ? ours : hostValue),
+        set: (v) => { if (document.currentScript === s) ours = v; else hostValue = v },
+      })
+      trapped = true
+    } else if (own.writable) {
+      window[globalName] = undefined
+    }
+    const restore = () => {
+      if (trapped) {
+        delete window[globalName]
+        if (own || hostValue !== undefined) {
+          Object.defineProperty(window, globalName, { value: hostValue, writable: own ? own.writable : true,
+            configurable: true, enumerable: own ? own.enumerable : true })
+        }
+      } else if (own && own.writable) {
+        window[globalName] = hostValue
+      }
+    }
+    s.onload = () => {
+      const got = trapped ? ours : window[globalName]
+      restore()
+      if (got) resolve(got)
+      else { cache.delete(pin.url); reject(new Error(`${globalName} loaded but exported nothing (an AMD loader on the page?)`)) }
+    }
+    s.onerror = () => { restore(); cache.delete(pin.url); reject(new Error(`${globalName} failed to load (network or integrity)`)) }
+    document.head.appendChild(s)
+  })
+  cache.set(pin.url, p)
+  return p
+}
diff --git a/package.json b/package.json
index 738392c2f..ab16932c8 100644
--- a/package.json
+++ b/package.json
@@ -138,6 +138,7 @@
     "check:packet-strings-parity": "node internal/check-packet-strings-parity.mjs",
     "check:packets-all": "node internal/check-packets-all.mjs",
     "check:parse": "node internal/inline-parse-check.mjs",
+    "check:pinned-umd": "node internal/check-pinned-umd.mjs",
     "check:popup-escaping": "node internal/check-popup-escaping.mjs",
     "check:poster-card-fits": "node internal/check-poster-card-fits.mjs",
     "check:poster-degrades": "node internal/check-poster-degrades-honestly.mjs",
@@ -198,7 +199,7 @@
     "dev": "bun x vite",
     "fix:sri": "node internal/fix-sri.mjs",
     "gallery": "node internal/generate-gallery.mjs",
-    "gates:post": "node internal/run-parallel.mjs --label=post -- check:drop check:parse verify check:sri check:public-hygiene check:label-joins check:facet-cascade check:facet-one-field check:heartbeat check:kpi-unit check:composite-reg check:descriptions check:no-abs-paths check:no-codename check:dep-names check:composite-srcs check:embed-targets check:nested-token check:i18n-parity check:tabs-localized check:packets-all check:packet-strings-parity check:zone-census check:share-policy check:library-index check:csv-shape check:capability-citations check:catalog-identity check:no-orphan-gates check:quoted-scripts check:done-evidence check:script-flags check:backlog-status check:capability-exemplars check:packet-fixture check:packet-browser check:provider-switch check:locale-reachable check:url-resolver check:manifest-covers check:one-palette check:pin-dim-slider check:legend-source check:backlog-refs check:clustering-modes check:composite-embed-knobs check:composite-locale-leaks check:linked-vocabulary check:wp-embed check:dashboard-geocoder-provider check:leaf-engine-per-provider check:map-props-unit check:composites-mount check:composite-interop check:no-free-identifiers check:map-fly-reduced-motion check:mst-clustering check:list-prop-unit check:profiles-mount check:cdn-pins check:no-eval check:popup-escaping check:i18n-treeshake",
+    "gates:post": "node internal/run-parallel.mjs --label=post -- check:drop check:parse verify check:sri check:public-hygiene check:label-joins check:facet-cascade check:facet-one-field check:heartbeat check:kpi-unit check:composite-reg check:descriptions check:no-abs-paths check:no-codename check:dep-names check:composite-srcs check:embed-targets check:nested-token check:i18n-parity check:tabs-localized check:packets-all check:packet-strings-parity check:zone-census check:share-policy check:library-index check:csv-shape check:capability-citations check:catalog-identity check:no-orphan-gates check:quoted-scripts check:done-evidence check:script-flags check:backlog-status check:capability-exemplars check:packet-fixture check:packet-browser check:provider-switch check:locale-reachable check:url-resolver check:manifest-covers check:one-palette check:pin-dim-slider check:legend-source check:backlog-refs check:clustering-modes check:composite-embed-knobs check:composite-locale-leaks check:linked-vocabulary check:wp-embed check:dashboard-geocoder-provider check:leaf-engine-per-provider check:map-props-unit check:composites-mount check:composite-interop check:no-free-identifiers check:map-fly-reduced-motion check:mst-clustering check:list-prop-unit check:profiles-mount check:cdn-pins check:no-eval check:popup-escaping check:i18n-treeshake check:pinned-umd",
     "gates:pre": "node internal/run-parallel.mjs --label=pre -- check:template-literal check:mjs-parse check:sfc-parse check:tab-radius check:synced-css check:doc-scripts",
     "library-index": "node internal/generate-library-index.mjs",
     "lists": "node library/scripts/people-groups/build-lists.mjs",
@@ -328,6 +329,7 @@
     "check:packet-strings-parity": "the PACKET catalog (packet-strings.json) must be whole in every language: all string keys, all 12 prayer points with every field, all 12 wheel rhythms. check:i18n-parity covers library/i18n/locales only — six gates READ this file and none checked it. Asserts PRESENCE, not translatedness, with point4_passage declared-absent on record.",
     "check:packets-all": "runs check:packet-render over EVERY generated packet, not one hand-named file. The single-file gate SKIPs with no argument, so it was in package.json, passing in all 11 locales, and in neither gates:pre nor gates:post — it only ran when someone typed a filename. SKIPs when no packets are generated.",
     "check:pin-dim-slider": "the side menu's pin-dim slider and the legend's dimming must COMPOSE, not compete. Both want the pin layer's circle-opacity, so there is ONE writer and the value is the PRODUCT: slider x (1 matched, 0 dimmed). Asserts the LIVE paint property, not the store: flat 1 with clustering off, flat 0.5 with clustering on, ['case', expr, 0.5, 0] once something is dimmed, and ['case', expr, 1, 0] when the slider returns to 1. Dims by RELIGION deliberately - a region selection sets a layer FILTER rather than an opacity expression, so testing that path would report a failure about code that never writes opacity.",
+    "check:pinned-umd": "library/utils/loadPinnedUmd.js (d3 for PPLR and the Wall) loads a pinned UMD with SRI and never touches the host page's global of the same name: a host's own d3 gains no keys, a failed load leaves it in place. Headless.",
     "check:popup-escaping": "the library's pin and region popups render hostile data (an <img onerror>, a <script>, a javascript: URL) as text, never markup: every field goes through escapeHtml/safeUrl (library/utils/html.js). Headless.",
     "check:poster-card-fits": "a poster card's print-options row must stay inside its own card. Reported by the repo agent off a 1440px screenshot: 27/27 cards overflowing by 110px, 36 neighbour intrusions. .pfs already had width:82%, so SOURCE READING SAID IT WAS FINE — flex items default to min-width:auto and refuse to shrink. Asserts BOTH no-overlap AND that the controls keep a usable box, because a row whose buttons collapsed to nothing would also \"not overflow\". Sweeps 390/768/1024/1440/1920px and asserts the row sits BELOW the preview too — measuring only left/right edges is how it passed a driver-visible regression. CARD_FIT_WIDTH overrides the list. SKIPs when nothing is served.",
     "check:poster-degrades": "with NEITHER poster nor source — the DEFAULT drop — nothing must print and the reader must be told why. check:poster-print-fallback SKIPs that case, so the behaviour a reader most often meets had no gate. MUST be served from the TREE ROOT, not public/, or assetsBase resolves outside the tree and the poster loads when it should 404.",
diff --git a/plugin-designs/pplr-data-maps/src/utils/pplrData.js b/plugin-designs/pplr-data-maps/src/utils/pplrData.js
index 6b4248506..320ceebf8 100644
--- a/plugin-designs/pplr-data-maps/src/utils/pplrData.js
+++ b/plugin-designs/pplr-data-maps/src/utils/pplrData.js
@@ -7,6 +7,7 @@
  * pplr/<file>. The files are derived by ../scripts/build-data.mjs into data/pplr/.
  */
 import { CDN, pinElement } from '@map/constants/cdn.js'
+import { loadPinnedUmd } from '@map/utils/loadPinnedUmd.js'
 let base = './assets'
 export function setDataBase(b) { if (b) base = String(b).replace(/\/+$/, '') }
 export function dataUrl(file) { return base + '/pplr/' + file }
@@ -16,63 +17,13 @@ export function dataUrl(file) { return base + '/pplr/' + file }
 // window.d3, overwriting a host page's own d3, or running on whatever d3 the host already had. Now one
 // exact version with integrity + crossorigin, captured here (pplrD3()), and the host's window.d3
 // put back exactly as it was.
-const D3_URL = 'https://cdn.jsdelivr.net/npm/d3@7.9.0/dist/d3.min.js'
-const D3_SRI = 'sha384-CjloA8y00+1SDAUkjs099PVfnY2KmDC2BZnws9kh8D/lX1s46w6EPhpXdqMfjK6i'
 let d3Lib = null
-let d3Promise = null
 export function pplrD3() { return d3Lib }
+// d3 7.9.0, pinned with SRI and kept off the host's window.d3: the shared loader
+// (library/utils/loadPinnedUmd.js) that this file and the Wall each used to carry a copy of.
 export function ensureD3() {
   if (d3Lib) return Promise.resolve(d3Lib)
-  if (typeof window === 'undefined') return Promise.reject(new Error('no window'))
-  if (!d3Promise) d3Promise = new Promise((res, rej) => {
-    const s = document.createElement('script')
-    s.src = D3_URL
-    s.integrity = D3_SRI
-    s.crossOrigin = 'anonymous'
-    // ★ PUTTING THE HOST'S window.d3 BACK IS NOT ENOUGH. d3's UMD build writes its exports INTO an
-    // existing window.d3 — `(t = globalThis).d3 = t.d3 || {}` — so a host that owns a d3 had ours
-    // written over it before we restored it: rega measured 577 added keys and version '7.9.0' on a
-    // host's own object (a host on d3 v6 would get v7 functions). So while OUR script executes
-    // (document.currentScript === s), window.d3 reads and writes a fresh slot of ours; any other code,
-    // at every moment, reads and writes the host's own value. Nothing is blanked while the file loads.
-    const own = Object.getOwnPropertyDescriptor(window, 'd3')
-    let hostD3 = window.d3
-    let ours
-    let trapped = false
-    if (!own || (own.configurable && 'value' in own)) {
-      Object.defineProperty(window, 'd3', {
-        configurable: true, enumerable: own ? own.enumerable : true,
-        get: () => (document.currentScript === s ? ours : hostD3),
-        set: (v) => { if (document.currentScript === s) ours = v; else hostD3 = v },
-      })
-      trapped = true
-    } else if (own.writable) {
-      // A `var d3` global is non-configurable, so it cannot be trapped: empty it for the load instead
-      // (the host reads undefined until onload), which still keeps our exports out of its object.
-      window.d3 = undefined
-    }
-    const restore = () => {
-      if (trapped) {
-        delete window.d3
-        if (own || hostD3 !== undefined) {
-          Object.defineProperty(window, 'd3', { value: hostD3, writable: own ? own.writable : true,
-            configurable: true, enumerable: own ? own.enumerable : true })
-        }
-      } else if (own && own.writable) {
-        window.d3 = hostD3
-      }
-    }
-    s.onload = () => {
-      const lib = trapped ? ours : window.d3
-      restore()
-      d3Lib = lib
-      if (d3Lib) res(d3Lib)
-      else { d3Promise = null; rej(new Error('d3 loaded but exported nothing (an AMD loader on the page?)')) }
-    }
-    s.onerror = () => { restore(); d3Promise = null; rej(new Error('d3 failed to load (network or integrity)')) }
-    document.head.appendChild(s)
-  })
-  return d3Promise
+  return loadPinnedUmd(CDN.d3, 'd3').then((d3) => (d3Lib = d3))
 }
 
 // The 17 locale names per PG, split out of pg-points so the first paint stays small. Loaded on
diff --git a/plugin-designs/wall-of-people-groups/src/wallD3.js b/plugin-designs/wall-of-people-groups/src/wallD3.js
index a49497750..061f5f026 100644
--- a/plugin-designs/wall-of-people-groups/src/wallD3.js
+++ b/plugin-designs/wall-of-people-groups/src/wallD3.js
@@ -5,66 +5,19 @@
  * as a script tag, so it (a) could change underneath every partner without notice and (b) became
  * `window.d3`, overwriting a host page's own d3, or, if the host already had one, the Wall ran on
  * whatever version the host shipped. Now: one exact version, `integrity` + `crossorigin`, and the
- * library is captured into this module and the host's `window.d3` put back exactly as it was.
+ * library is captured into this module and the host's `window.d3` put back exactly as it was. The
+ * loader itself is shared with pplr-data-maps: library/utils/loadPinnedUmd.js.
  */
-const D3_URL = 'https://cdn.jsdelivr.net/npm/d3@7.9.0/dist/d3.min.js'
-const D3_SRI = 'sha384-CjloA8y00+1SDAUkjs099PVfnY2KmDC2BZnws9kh8D/lX1s46w6EPhpXdqMfjK6i'
+import { CDN } from '@map/constants/cdn.js'
+import { loadPinnedUmd } from '@map/utils/loadPinnedUmd.js'
 
 let lib = null
-let loading = null
 
 /** The Wall's own d3 (null until ensureD3() has resolved). */
 export function wallD3() { return lib }
 
+/** d3 7.9.0, pinned with SRI, kept off the host's window.d3 (library/utils/loadPinnedUmd.js). */
 export function ensureD3() {
   if (lib) return Promise.resolve(lib)
-  if (typeof window === 'undefined') return Promise.reject(new Error('no window'))
-  if (!loading) loading = new Promise((resolve, reject) => {
-    const s = document.createElement('script')
-    s.src = D3_URL
-    s.integrity = D3_SRI
-    s.crossOrigin = 'anonymous'
-    // ★ PUTTING THE HOST'S window.d3 BACK IS NOT ENOUGH. d3's UMD build writes its exports INTO an
-    // existing window.d3 (`(t = globalThis).d3 = t.d3 || {}`), so a host that owns a d3 had ours
-    // written over it before we restored it (rega measured it on PPLR: 577 added keys, version
-    // '7.9.0' on the host's object). While OUR script executes (document.currentScript === s),
-    // window.d3 reads and writes a fresh slot of ours; any other code, at every moment, sees the
-    // host's own value. Same fix as pplr-data-maps (60faff1a), which rega re-ran PASS in 3 variants.
-    const own = Object.getOwnPropertyDescriptor(window, 'd3')
-    let hostD3 = window.d3
-    let ours
-    let trapped = false
-    if (!own || (own.configurable && 'value' in own)) {
-      Object.defineProperty(window, 'd3', {
-        configurable: true, enumerable: own ? own.enumerable : true,
-        get: () => (document.currentScript === s ? ours : hostD3),
-        set: (v) => { if (document.currentScript === s) ours = v; else hostD3 = v },
-      })
-      trapped = true
-    } else if (own.writable) {
-      // A `var d3` global is non-configurable, so it cannot be trapped: empty it for the load instead.
-      window.d3 = undefined
-    }
-    const restore = () => {
-      if (trapped) {
-        delete window.d3
-        if (own || hostD3 !== undefined) {
-          Object.defineProperty(window, 'd3', { value: hostD3, writable: own ? own.writable : true,
-            configurable: true, enumerable: own ? own.enumerable : true })
-        }
-      } else if (own && own.writable) {
-        window.d3 = hostD3
-      }
-    }
-    s.onload = () => {
-      const got = trapped ? ours : window.d3
-      restore()
-      lib = got
-      if (lib) resolve(lib)
-      else { loading = null; reject(new Error('d3 loaded but exported nothing (an AMD loader on the page?)')) }
-    }
-    s.onerror = () => { restore(); loading = null; reject(new Error('d3 failed to load (network or integrity)')) }
-    document.head.appendChild(s)
-  })
-  return loading
+  return loadPinnedUmd(CDN.d3, 'd3').then((d3) => (lib = d3))
 }