Pinging the OP here, @rotor
Could you confirm the request here a bit?
As far as I understand, you are requesting to Log in to your account with the use of a Passkey (which as discussed is just WebAuthn under the hood so adding this would also allow Log in with a Yubikey or the like) which would allow for a seamless and Passwordless Login experience similar to the current Log in with Device feature available.
Otherwise, as mentioned current Apple, Google, and Microsoft Passkeys would be supported as a premium 2FA method that can be used with your Master Password on Log in in place of a YubiKey, or in conjunction with as you can have up to 5 associated within your account.