FIDO2 is nice and all.
I do want a good pgp/ssh compatible card with Curve225519 and can’t find one - yubikey has RSA and P384 iirc, but none have 25519.
(I need to sign data often; rsa 2048, the minimum rsa length acceptable at this point, is both slow on hardware elements and very long)
Seriously, this is my exact use case. I am using a yubikey with rsa 2048 right now, and I want something a bit stronger. Inexplicably, the Somu stretch goals start with ECDSA then go to Ed25519. Not that either will be reached anytime soon, or that reaching a stretch goal on a crowd funded campaign magically makes the feature appear.
Note that the ed25519 is not as easy as it seems, ssh agent doesn’t support it yet. I wrote a couple notes/details in the somu campaign you linked, towards the end.