This is ultimately why I haven't made the leap to Yubikey style auth. My backup plan depends ultimately on something I know (the password to a backed up copy of

This is ultimately why I haven't made the leap to Yubikey style auth. My backup plan depends ultimately on something I know (the password to a backed up copy of my password vault which contains 2fa codes for essential services, and backed up totp codes which are encrypted with a password in that vault for the rest).