Common things in JoJo fics I Dislike

General Complaints: Oh hello Author

This is a pretty minor issue, but it can get annoying quick and seems a tad on the unprofessional side imo.
But please for the love of DIO, do NOT interrupt your story for an Author's note unless it contains information that is necessary for your readers! I.e. scientific/ historical facts

Even then, I think that kind of info should be told before the chapter starts or at the end of it.

Reader's don't need your commentary and some do not want it either.