You mean if you get a cut on the finger you registered. On this page[1], though, it says it would support "[storing] multiple fingerprints", so that should help in that case.

[1] https://www.yubico.com/products/yubikey-hardware/

Hmmm, I wonder if there's a way to set this up with a "duress" fingerprint, that'll unlock a special/different key and log you in to completely vanilla accounts instead of your real ones?

That is a must, I recently started skateboarding and wipping it up and grabbing the sanding paper-like surface makes my fp scanner not work for about 2 days!

Hot tip for guitarists: left thumb fluctuates least.

I currently have multiple keys. One I carry on me and one I locked in our firesafe with other important documents.

The way I see it, I would want the bio version to be the one on my person. I still have the other put away where it won't be lost.

I lose my hand? Still have a backup. I lose my key? Backup and maybe I have a little bit of extra time to update my bank MFA while the thief figures out the fingerprint situation.

What services even support multiple keys?

That's been my biggest struggle, I want a primary and backup key but almost every service I use only allows one at a time. I cannot duplicate the same key because it increments internally to avoid replay.

Not as many as I would like, but: google, github, hetzner, ovh, gandi, gitlab, bitwarden are some that support multiple keys.

I suppose for sites that only allow one, you can store their backup codes in bitwarden behind you multi-key service. Still annoying.

Facebook, GitHub and Google are common sites which allow multiple keys.

Is there a service that limits to a single key? I've never encountered one.

AWS only allows one U2F token to be registered at a time.

Zoho.

twitter. :(

Google does, and IIRC Github does too.