There is also a authy-export tool that makes it pretty easy to export all the tokens to selfhosted pass repo.

do you have two or more yubikeys? how do you handle sites that only allow registering a single webauthn dongle? how do you handle backup 2fa?

loosing my yubikey is the main reason why i havent used it yet for webauthn. I just use pass and openpgp keys stored on the yubikey as that way it was possible to backup the encryption private key to a seperate usb drive that can be used to restore it later if needed.