Another layer of indirection often solves things in software engineering. You need a key store that allows use control via multiple identity sources so a backup

Another layer of indirection often solves things in software engineering. You need a key store that allows use control via multiple identity sources so a backup path can add remove or update allowed sources. If google locks a particular account, drop it as an allowed source, add a different one. This of course expands the attack surface - indirection comes at a cost.