I consider buying a new Nitrokey to store both my OpenPGP and SSH keys. Both are Ed25519 keys. The OpenPGP has SC capability for the primary key and E for the sub-key. The SSH key would be the equivalent of an OpenPGP key with A capability I presume.
Now the Nitrokey documentation is quite helpful to learn how to store an OpenPGP key with SC, E and A capabilities. I did not find instructions to add the SSH key as a OpenPGP sub-key with A capability substitution though.
Considering that storing SSH in a Nitrokey is advertised on the website, how could one achieve that?
And which Nitrokey would support that considering the keys are both Ed25519 (Nitrokey Start or Nitrokey 3)?