pass.
It’s simple and has frontends for all my usecases. It’s so simple, that you can extend it’s functionality yourself if you wish.
Synchronizing works by just synchronizing the folder where the data lives, so syncthing, git, dropbox, ftp. Whatever you like.
No, it doesn’t really make sense for 2fa to have both factors in the same database, I use yubikeys with webauthn.