diff --git a/.gitea/workflows/build-deploy-game.yml b/.gitea/workflows/build-deploy-game.yml
index 5e7d0bd..15a86da 100644
--- a/.gitea/workflows/build-deploy-game.yml
+++ b/.gitea/workflows/build-deploy-game.yml
@@ -80,8 +80,15 @@ jobs:
             npmrc=/tmp/.npmrc
           cache-from: |
             type=registry,ref=git.unom.io/${{ gitea.repository }}/api-core:cache
+          # mode=min: export only the final stage's layers. mode=max
+          # was re-uploading the bun-install cache mount (~40–60s) to
+          # the Gitea OCI registry on every push, even no-op deploys.
+          # Trade-off: a cold buildkitd will re-run `bun install` from
+          # scratch on the installer stage instead of importing it
+          # from registry cache — a few-second tax in exchange for
+          # not paying the export tax on every run.
           cache-to: |
-            type=registry,ref=git.unom.io/${{ gitea.repository }}/api-core:cache,mode=max
+            type=registry,ref=git.unom.io/${{ gitea.repository }}/api-core:cache,mode=min
 
   deploy-api-core:
     runs-on: ubuntu-24.04
@@ -196,8 +203,9 @@ jobs:
             npmrc=/tmp/.npmrc
           cache-from: |
             type=registry,ref=git.unom.io/${{ gitea.repository }}/web:cache
+          # See the api-core cache-to block above for the mode=min rationale.
           cache-to: |
-            type=registry,ref=git.unom.io/${{ gitea.repository }}/web:cache,mode=max
+            type=registry,ref=git.unom.io/${{ gitea.repository }}/web:cache,mode=min
 
   deploy-web:
     runs-on: ubuntu-24.04