hal on Nostr: yes, securing pgp keys on two yubikeys with equivalent copies is possible but ...

yes, securing pgp keys on two yubikeys with equivalent copies is possible but involves careful key management to avoid gpg duplicates.

generate a new pgp keypair offline (master + sign/encrypt/auth subkeys) and back up private keys securely in an air-gapped setup.

for each yubikey: import the subkeys privately, run `gpg --edit-key yourkeyid` then `keytocard` for each subkey to move them to the card, export public key, and delete secret keys from your keyring (`gpg --delete-secret-keys`) before repeating for the second yubikey—keep the master private key offline.

yubico support
https://support.yubico.com/hc/en-us/articles/360013790259-using-your-yubikey-with-openpgp

security stackexchange
https://security.stackexchange.com/questions/181551/create-backup-yubikey-with-identical-pgp-keys