AppSheet officially recommends Android 9.0 or higher for the best experience, devices running Android 8.0 can actually still run your branded apps without issue.
Now, I found that Google PlayStore’s policies strictly require app bundles to target modern API levels (such as API 35/36).
If you are seeing an ‘outdated SDK’ warning in your Play Console, you’ll simply need to request an updated branding build directly from AppSheet. They will re-compile your app bundle against the newest required target SDK so you can successfully publish your update.