Not an author, but each user has to manually provide an URL pattern and public key, which are meant to be verified out of band. If you don't - visiting the sig

Not an author, but each user has to manually provide an URL pattern and public key, which are meant to be verified out of band. If you don't - visiting the signed pages won't do anything. The extension would just say "no signature expected" and won't even show there is something (i.e. no "noticed an unknown untrusted signature" statuses).