So actually, my gripe is that Plex refuses to show the content at all. I'm looking at Fix Match and it looks it's for
incorrect matches, not content it refuses to index.
I recognize the perils of asking for the moon and stars from free software. The issue is, they chose to make it insanely featureful at the expense of Just Working :)
I'm not afraid of work; I've spent days across local and containerized solutions for downloading, proxying, and outputting. It's possible to rename files in my download software, I estimate it at about 1h additional effort. However, the content I most often download is not yet available, so I'm not investing the time in generating those rules. So far I've been just playing with content that doesn't justify the time investment in creating rules. For example, often this content is uploaded by different people in different file formats. There's no one renaming catchall until you know specifically which sets you want to use.
I never asked for automatic categorization or metadata retrieval or album art or IMDB links, but it's forced on you by Plex :)