Can the .plexmatch files be utilized in order to add items to collections automatically?
Also, is there a complete list of tags that can be used for these files (the official “guide” came off as a bit thin), so those of us who are going to utilize it can do it right from the start, instead of having to go back and update those files later.
No, they’re only used to associate (often “incorrectly” named) folders/files with the right show/season/episode. So I could tell Plex that TV/SomeShow/SomeShow Episode1.mkv is actually “Season 1, Episode 1 of Some Show (2000)”, instead of renaming the file to match Plex’s guidelines of TV/Some Show (2000)/Season 01/Some Show - S01E01.mkv.
What kind of tags are you expecting to use? .plexmatch can’t be used to e.g. set the director of the show, or add a label to a show, you can only use the keywords/patterns mentioned in the article AFAIK.