When PGP is used for two factor authentication by sending the user an encrypted one-time URL to use as a login page this link is usually also signed to help against phishing attacks but not in the nice combined way.

Rather a clearsigned message is encrypted. Similar to PGP/MIME where usually a multipart/signed is encapsulated in a multipart/encrypted part. So after decryption it would be nice if the notepad would automatically verify a clearsigned message if it detects it in the cleartext.