Speaking of Harry Mudd...although this is not canon, is ALMOST WAS...there were plans for a Harry Mudd episode of The Next Generation. I remember reading about it way back in the day, I THINK in the Official Fan Club Magazine, as is was called back then. In the Episode, the Enterprise-D crew was going to have found a pod floating in space with a cryogenic pod, with a frozen Harry Mudd. There wasn't much in the article about the main plot details, but I remember it was going the have a scene where Mudd was going to have so opportunity to get rich, but somehow the Enterprise was in danger of being destroyed, likely as part of whatever Mudd's plan was, and at the very last minute he was going to choose to save the Enterprise crew, and say "This one's for Kirk and Spock!"
WHICH...would kinda be a bit out of character for the...um...character...but maybe they would have implied that Mudd had MORE run-in's with Kirk and Spock and the Enterprise crew, and he lightened up!? Maybe!?
Unfortunately the actor died before the episode could be filmed...and I got the idea that the episode was never even in the production schedule, but that if it had, it would have been like like the first or second season, and that would have violated Gene's rule about not mentioning Kirk or Spock or any of the original crew...for some dumb reason.
Really too bad it was never made.
Edited to add: Looking at the date the Roger C. Carmel died, in November 1986, this would have had to have been an episode considered for season 1, but obviously would have had to have been abandoned with the actor's passing.