Seems I guessed right, thanks for explaining it.
Yes, to be safe I assumed I would need to delete and install and also assumed I would need to start from step 3 in the first post again, but since I was already signed in with the Google ID the Play Store just worked right away and I successfully installed an app with a saved apk. This is really incredible Cobalt, I don't think you can be thanked enough for contributions like this to our community so thanks again for your hard work!
Posted via CB10