Each function can have 2FA enabled using different methods. For example, you may choose to use the Passkey method for the sign-in function because Passkeys are the most convenient and secure to use in daily life. Then for your Master Key function, you may choose to use the authenticator app method because it is less convenient to use and not needed as frequently. The Master Key is only needed in the rare case when you've lost your sign-in 2FA, have to change your password or need to remove the GSL immediately.Having sign-in 2FA and the Master Key on the same device cancels out the security that these functions guarantee when kept separate. The 2FA method used for the Master Key should be different from the one used for your sign-in 2FA, otherwise it defeats the purpose of the Master Key.