What's the deal with lost yubikey user workflow? Rely on individual websites to give you a one-time recovery passcode that you then have to input into every website? I can't believe I'm taking UX cues from cryptocurrencies, but what about providing the user with a seed for the yubikey private key they can back-up offline then reinstall in a new yubikey?

P.S. just ordered a yubikey security key, excited to add this additional layer to my own personal byzantine security labyrinth. Or maybe simplify it, who knows!