I spent some time working on this tool called PlexPreferNonForcedSubs. It’s basically just a simple Python script that sets all movies and shows in your local Plex library to English non-forced subtitles by default. The subtitle preferences are applied to your Plex profile and remembered on other devices. The project’s GitHub repository and source code can be found here.
It’s very easy to setup. First you need Python. Then to install run python -m pip install PlexPreferNonForcedSubs in command line. Then run it by calling PlexPreferNonForcedSubs in command line. It will ask to to enter your plex token on first run. Alternatively, you can download the latest release on GitHub and place it in the directory of your choice.
If this is something you would find useful feel free to give it a try and let me know what you think! It is confirmed working on Windows and should run fine on MacOS and Linux. But please do share your experience and open any issues on Github if you run into any bugs. Happy to accept issues and pull requests!
Screenshot:
