> All the services that I have used with U2F support have supported multiple keys. Google, Gitlab, Github, and some others which I forget.
I've run into a number of services that only allow a single U2F key (it's been a while, so I don't remember the exact ones). Even if they do support multiple U2F keys, how do you handle enrolling both? I keep my backup key offsite, so ideally I could enroll it without physically possessing the device. If I have both in my possession at all times (or even sometimes), I'm at risk of losing both of them.
I've run into a number of services that only allow a single U2F key (it's been a while, so I don't remember the exact ones). Even if they do support multiple U2F keys, how do you handle enrolling both? I keep my backup key offsite, so ideally I could enroll it without physically possessing the device. If I have both in my possession at all times (or even sometimes), I'm at risk of losing both of them.