Don’t know if it will help, but I had a lot of frustration trying to do this. Below is the solution that worked for me. In short, I manage my files and the metadata for them, then just let Plex play them for me. Plex is software and software is always buggy and frustrating, so just dealing with the files makes it so much easier. Most “mp3 tag” editors should work.
Outside Plex: I edited the metadata and set the “Album Artist” metadata for each to be the name of the show. That’s helps with sorting.
Outside Plex: Having the file names starting with the date allows them to play on in the right order. I guess you could also set the play order with metadata but I didn’t do that.
Outside Plex: I downloaded album art and embedded it with the metadata.
In Plex: I made a music library for my otr files called “OTR”.
In Plex: , setting the library to “store track progress” allowed me to continue where I left off.
When I find an error somewhere I fix it in metadata then do the “Plex dance” (use search bar if unfamiliar with that). If that doesn’t fix it, then I delete the library and recreate it. Since all my info is stored in the files and not in Plex, deleting and recreating causes no harm.
TLDR: Use Plex to serve the files, not manage them. Manage the files using metadata.
