Another idea: if you had a passkey on your phone then that could be used with biometrics to unlock something (in theory… as it’s not implemented in Bitwarden at the moment)… and then, we would arrive at this next feature request: Unlock with FIDO2/“passkeys”
PS: And as I understand biometrics, those only work - in a stricter sense - locally on the same device. Biometrics on your phone don’t have a direct connection to the browser extension on your desktop computer or laptop. – So I would think, either “Unlock with device” or “FIDO2/“passkey”-unlock” would be good candidates for what you’re asking.