diff --git a/plugin-designs/big-picture/big-picture.vue b/plugin-designs/big-picture/big-picture.vue
index 669ce5b89..ef0c694a7 100644
--- a/plugin-designs/big-picture/big-picture.vue
+++ b/plugin-designs/big-picture/big-picture.vue
@@ -126,6 +126,12 @@ watch(textDir, reflectDir)
 const listConfig = computed(() => {
   const cfg = {}
   if (config.value.list) cfg.list = config.value.list
+  // ⚠ THE SPELLING IS LOAD-BEARING AND THE TWO SIDES DO NOT MATCH BY NAME. This writes `lang`; the
+  // grid's prop is `languageCode`. It works because people-groups-grid.vue accepts three spellings —
+  // languageCode || locale || lang — and `lang` is the THIRD of them. Rename or "tidy" either side
+  // without the other and a composed grid silently renders in the wrong language on a profile-config
+  // embed, which is the exact failure 8b40f6c58 was written to fix and which no gate would catch:
+  // ?lang= embeds keep working, so only a host passing profile-config sees it.
   if (hostLang.value) cfg.lang = hostLang.value
   return Object.keys(cfg).length ? JSON.stringify(cfg) : ''
 })
diff --git a/plugin-designs/people-groups-grid/people-groups-grid.vue b/plugin-designs/people-groups-grid/people-groups-grid.vue
index 49c1b2d81..c0fd6b6f9 100644
--- a/plugin-designs/people-groups-grid/people-groups-grid.vue
+++ b/plugin-designs/people-groups-grid/people-groups-grid.vue
@@ -261,6 +261,11 @@ const prayBaseUrl  = computed(() => props.prayBaseUrl || cfg.value.prayBaseUrl |
 // localeFromUrl() is the library's own reader, imported rather than re-implemented, so the fetch and
 // the chrome can never disagree about what the URL asked for. Same ladder regions uses
 // (region-dashboards.vue:95), and a host that passes languageCode still wins.
+// ⚠ ALL THREE SPELLINGS ARE IN USE AND `lang` HAS A CALLER. big-picture composes this grid and threads
+// the host's locale into its profile-config as `lang` (big-picture.vue, listConfig) — it cannot reach
+// this bundle any other way, because getRuntimeLocale is module state and a separately-built child gets
+// its own copy. Dropping `cfg.value.lang` from this chain would leave a composed grid in the wrong
+// language on a profile-config embed while ?lang= embeds carry on working, which is how it would ship.
 const languageCode = computed(() =>
   props.languageCode || cfg.value.languageCode || cfg.value.locale || cfg.value.lang || localeFromUrl() || '')