> I don't think that reputation really should transfer anyway

Why not? The most important security bits are implemented client-side which is developed by Bitwarden. If the clients are secure then my database is safe even if Vaultwarden turns out to be evil.

Switching from Bitwarden Client to Vaultwarden Client would require about 3 orders of magnitude more trust than switching the server which primarily deals with encrypted blobs. If the client turns out to be malicious then it's game over.