I'm looking to make use of a useless Ledger Nano S and a Keystone Pro I have lying around. Maybe as part of a multisig?

I have too many old "useless" (for singlesig) signers.

Bitkey is also one of em but can't even add that to a multisig.

Might just get a Jade and make a 2of3 multisig with Jade, Nano S, Keystone (?)