The readme specifically mentions Yubikey support. Given the restrictions with Secure Enclave (no import, export, or backup), a smart card or Yubikey probably would be better.
Any idea how to set my YubiKey up to handle this?
I can recommend this guide [1] to setup your yubikey with gpg, which allows you to both use it to sign or encrypt with gpg and also to use it as an ssh key.