I wanted to do it myself, learn and getting used to dev things again. AI are often wrong on some details but I used it sometimes and it can help a lot for parts of code or understanding some things.

That's what I already did. And finding the good mkvpropedit command was long.
But here I wanted to automate that and just having to choose the audio and subtitles languages and it executes the mkvpropedit command.

I know but I didn't fell completely at ease to share some mildly clean code. Now it's good. I put it in the comments.

Here it is. I took the time to comment it well and rearrange some things.
It's in 2 files :
https://pastebin.com/FQ7xqNSt
https://pastebin.com/6S3qesWc
Keep the file names I chose when copy/pasting. Read the loop file to see how to use it quickly.
I forgot to say in the loop script’s quick explanations that you need mkvmerge and mkvpropedit from MKVToolNix (put it in the PATH variable if needed) and nodejs to make that script work.

I could but I would have to comment it a little more. If I don't forget I'll share it later in response of your message.

This mouse model was made decades ago for the time when would come the chosen one. The scroll master. He's here to equilibrate the world with his scroll powers. Zoom in, zoom out. Volume up, volume down. Everything is possible, with, THE. DOUBLE. SCROLL. WHEEL.

Ok, so if it's the new standard then I should go with Kotlin. By boilerplate, do you mean a part of the code that makes java a little too heavy?

"Better looking drivers!"

Nice to see an Arrested Development meme.

I know. And you'll see, it's crazy when they get to activate the 8th chevron of the stargate.

I'm exactly like this.