Plex-Auto-Languages VS Movie_Data_Capture

My guess is that for both tracks the actual language code used is just Spanish, and it's just the title that indicates esp versus lat. In that case, since there are multiple tracks with the same language, Plex will pick the first track available. You might have to use something like PASTA or Plex Auto Languages for better control over selected audio/subtitles.

It might be easier to use something like PASTA to bulk-select the specific track you want, or Plex-Auto-Languages, which will give you a more Netflix-like experience where changing the track of one episode will go through all episodes in the season/show and automatically select a track of the same language/name if available.

I prefer plex-auto-languages personally because it’s automatic. You run it locally, and it monitors your TV show usage on Plex. When you play a TV episode with specific audio/subtitle settings, plex-auto-languages notices that and applies those same settings to every other episode in the show.

Sure here you go: https://github.com/RemiRigal/Plex-Auto-Languages

Outside of that, you'll have to use something like PASTA or Plex Auto Languages to bulk-update the selected audio/subtitle stream.

Since you have the remux, I'd just keep that, and select the right subtitle/audio stream when playing the file back. The major benefit there is that you don't need to have two copies of the same video stream just for different audio/subtitle tracks. The major downside is that if the audio/subtitles you want aren't the default, you have to manually change it for every episode, so for the best experience I'd combine that with a third-party script like Plex-Auto-Languages (a script that will change the audio/subtitle stream for all episodes in a season/show when one changes) or PASTA (a one-time bulk operation tool).

Original is here, I did next to nothing, all credit goes to them.

Not within Plex itself, but you can bulk-update a subtitle track for a season/show with PASTA. Plex-Auto-Languages does something similar by changing tracks for an entire season/show if you change the track for a single episode.