I appreciate the help offered to me, but unfortunately the given solutions are not viable solutions for me.
I can’t apply a kind of add/update file metadata solution that in my case implies to re-write about 32 Terabytes of video files (and anyways as per @OttoKerner’s comment it seems will not work with mkv for plex). It is an overkill, and inflexible solution to title fixes or modifications.
I can’t apply a solution that consists on manually editing fields for specific movies (or just only those that are part of a collections) in the plex web app, because there are thousands of movies. I can’t try to automate this task either, which maybe would be possible with a lot of effort developing a kind of mouse macro with OCR techniques, but it could take about a minimum of 10~15 seconds per movie so it’s a pain and a waste of time. It would take whole days in total just to do a full title update once on the server.
I need some kind of solution different than those.
If Plex adds support for specific fields in the .nfo file that Plex reads, let’s say “title=MY MOVIE TITLE”, it would be perfect. But Plex does not support that, or so I think. That would be programmatically easy to generate that file for every movie folder, with very low space usage, and easy to maintain it updated.
It would be really genius if Plex in general could add support via the .nfo file to override some more things appart from the movie title id for IMDB and that, which is very useful, but it feels incomplete if the .nfo only can serve us for forcing the movie title id. Maybe it could let the users to force other things, like the title, title sort, year, etc by adding support for fields in the format name=value.
In fact my .nfo file contents looks like this:
# The content of this file is used by Plex
# to identify the movie title.
IMDB Id=tt0133093
TMDB Id=N/A
TVDB Id=N/A
And I know it is totally unnecessary to write comment lines and things like field_name=value syntax haha, Plex does not parse the content in that way and I could remove absolutely everything except the IMDB title id and it will work, but I really like aesthetically how it looks with that syntax.