diff --git a/plugin-designs/my-upg-100-list/poster-wall.vue b/plugin-designs/my-upg-100-list/poster-wall.vue
index ee164d4d7..5938b5cc3 100644
--- a/plugin-designs/my-upg-100-list/poster-wall.vue
+++ b/plugin-designs/my-upg-100-list/poster-wall.vue
@@ -39,7 +39,7 @@
  * IDEA-POSTER-EXPORT-404-ON-DROPPED-FOLDER-TRADEOFF.
  */
 import { computed, inject, ref } from 'vue'
-import { useI18n } from 'vue-i18n'
+import { useOptionalT } from '@map/composables/useOptionalT.js'
 // The page's people-group LIST (library/lists/): every people-group fetch below keeps only its groups.
 import { applyPeopleGroupList } from '@map/lists/peopleGroupList.js'
 import PosterWall from '@map/components/poster/PosterWall.vue'
@@ -160,11 +160,22 @@ async function fetchListRecords(list) {
 // copy a reader reads FIRST was the untranslated part. The <strong> travels inside the
 // translated string so each language can emphasise its own words, which is not something a
 // wrapper around an English sentence could do.
-// Guarded like every other useI18n() here: it throws on a host without vue-i18n.
-const humanizeKey = (k) => String(k).split('.').pop()
-  .replace(/([a-z0-9])([A-Z])/g, '$1 $2').replace(/^./, (c) => c.toUpperCase())
-let t = (k) => humanizeKey(k)
-try { t = useI18n().t } catch (_) { /* no i18n on this host */ }
+// Guarded like every other useI18n() here: it throws on a host without vue-i18n. useOptionalT stores
+// that guard once (host i18n -> tStatic -> the key itself) instead of a fourth hand-rolled copy.
+//
+// ★ NO humanizeKey FALLBACK, and the reason is a MEASUREMENT, not a preference. That fallback rendered
+// a key's last segment title-cased, so a bare host showed "Upg100 Wall Intro" where a real sentence
+// exists. It was kept on the theory that these keys were not fully catalogued — I said so to
+// regions-plugin, and it was FALSE: this file's three keys are present in all ELEVEN locales, 0 gaps
+// (enumerated 2026-09-27; they are the only three, all string literals, no computed keys).
+// So the fallback was shielding nothing and costing the translation. tStatic honours the READER'S
+// locale with English as the last resort, which is strictly better than an English-ish word derived
+// from an identifier.
+// ⚠ IT GUARDS A BARE HOST, NOT A MISSING KEY — those are different failures and I had them confused.
+// Switching changes what seven vue-i18n-less bundles render, so it is a product decision: taken by
+// dx-shepherd (UPGHK, 2026-09-27) as carrying out the Driver's standing goal that the production maps
+// be localized. Not a consolidation I was entitled to make on my own.
+const t = useOptionalT('messages')
 const intro   = computed(() => t('messages.upg100WallIntro'))
 const heading = computed(() => t('messages.upg100WallHeading'))
 const wallTag = computed(() => t('messages.upg100WallTag'))
diff --git a/plugin-designs/my-upg-100-list/upg-100-mfe.vue b/plugin-designs/my-upg-100-list/upg-100-mfe.vue
index f9501aa2f..1fafb0ecf 100644
--- a/plugin-designs/my-upg-100-list/upg-100-mfe.vue
+++ b/plugin-designs/my-upg-100-list/upg-100-mfe.vue
@@ -34,7 +34,7 @@
  * whole MFE (both panes) is what gets shared/embedded.
  */
 import { ref, computed, inject, onMounted, onBeforeUnmount } from 'vue'
-import { useI18n } from 'vue-i18n'
+import { useOptionalT } from '@map/composables/useOptionalT.js'
 import { buildPaneColumn, PANE_GRID_STYLES } from '@map/layouts/pane-wrapper/pane-wrapper.js'
 import { useShadowStyles } from '@map/composables/useShadowStyles.js'
 import ViewSelect from '@map/components/ViewSelect.vue'
@@ -46,12 +46,19 @@ import ShareButton from '@map/components/map-controls/ShareButton.vue'
 // wrapper never did. The chrome a reader sees FIRST was the untranslated part.
 //
 // ⚠ GUARDED, like every other useI18n() call in this codebase: it THROWS on a host that has not
-// installed vue-i18n, and this component is mounted by hosts we do not control. The fallback
-// humanises the key so a bare host shows "Select View", never a blank or a raw dotted key.
-const humanizeKey = (k) => String(k).split('.').pop()
-  .replace(/([a-z0-9])([A-Z])/g, '$1 $2').replace(/^./, (c) => c.toUpperCase())
-let t = (k) => humanizeKey(k)
-try { t = useI18n().t } catch (_) { /* no i18n on this host */ }
+// installed vue-i18n, and this component is mounted by hosts we do not control. useOptionalT holds
+// that guard once — host i18n first, then tStatic, then the key — instead of a hand-rolled copy here.
+//
+// ★ THE humanizeKey FALLBACK IS GONE ON PURPOSE. It rendered a key's last segment title-cased, so a
+// bare host showed "Select View" — which reads fine in English and is simply WRONG for every other
+// reader, because it cannot be translated: it is derived from the identifier, not from a catalogue.
+// tStatic honours the reader's locale and still ends at English. The four keys this file uses
+// (tabs.map / prayerResources / selectView / views) are present in all ELEVEN locales, 0 gaps,
+// enumerated 2026-09-27 — so nothing here was relying on the fallback.
+// Product decision, taken by dx-shepherd (UPGHK) under the Driver's standing goal that the production
+// maps be localized: switching changes what seven vue-i18n-less bundles render, which is not a call a
+// consolidation gets to make for itself.
+const t = useOptionalT('tabs')
 
 const cfg     = inject('profileConfig', ref(null))
 const tk      = inject('mapboxToken', ref(''))