This. For a while I tried to keep a list of accounts I needed to add my offsite key to, and then every year or so I'd retrieve the key, and add in bulk, but that became way too complicated.

While not ideal, I'd be happy if I could register with the public key of my offsite key or something similar. Really I think there should be a way to register a public persona, and add / remove keys from that persona at will.

Or, just let me (somehow) generate multiple hardware devices with a shared seed.