solo-dicekeys

There is actually at least one fido2 device that supports backing up (mostly), based on this spec from Dicekeys https://github.com/dicekeys/seeding-webauthn Solokeys (https://solokeys.com/ - v1, don't think the newer v2 does) have a special firmware version that implements this and allows you to use a custom seed - and as such restore a key from it. It only works on non-resident credentials (most commonly used, as the number of RKs is usually very limited) though. The firmware is here https://github.com/conorpp/solo-dicekeys/releases/tag/5.0.0 But it's also shipped in the keys dicekeys sells and I think only their app implements the client side of seeding anyway: https://www.crowdsupply.com/dicekeys/dicekeys

This seems to refer to https://dicekeys.com, basically a number of dice mean to be used as seeds for cryptographic seeds I guess. From the little I understand you might need a custom firmware for your solo key https://github.com/conorpp/solo-dicekeys and then you can set the seed from the dicekeys app? Their release page seems to have more info https://github.com/conorpp/solo-dicekeys/releases/tag/5.0.0 As always, do some more research as that’s just from a cursory google into dicekeys and solo.