The author, Alex Haydock, has deleted all their traditional SSH keys and is transitioning to using hardware-resident keys for added security, despite acknowledging that using a passphrase with traditional keys is sufficient for most threat models. They are exploring three methods to hold and encrypt SSH key material using secure enclaves: YubiKey, Trusted Platform Module (TPM), and Apple Secure Enclave, aiming to eliminate unprotected key material stored on-disk. The author notes that while traditional keys with passphrases are encrypted and protected, they prefer the added security and satisfaction of using hardware-backed keys, and documents their experience with these alternative methods.