I’ve made numerous renames and I’ve never needed to do a Plex Dance afterward. Plex should re-crawl the files and update them accordingly when you do a manual scan. For movies that are already correctly named, it should simply leave them alone, except for adjusting the source filename that it plays.
BTW I also went through this: Realizing that adding the year helps Plex a lot. It was before software that automated the process. That was tiring the old fashioned way.
