You totally could replicate the nsecbunker "google-like" auth flow on the clients where rather than whitelisting a delegate key, this additional bunker just sends over the encrypted client secret. The important thing is that you aren't trusting a single entity with >= the threshold shares necessary to craft a valid signature. As long as that remains true, you can still safety rotate keys and know that any single malicious entity could not rug you.

How do we encrypt/decrypt DMs with Frost?