@Maverynthia I hope you'll feel better soon ^_^

If you use the batch variant, be sure to check that every one of the files has the correct soundtrack afterwards before deleting the old files.
If the tracks aren't in the same order it will happily reencode the other audio track or fail because it's a video or subtitle track and then reuse the audio from the previous video file :o
Protect against the latter by adding a line between the bn=... and ffmpeg... ones like this:
> rm -f ♬.ac3

Yeesh. You should've just said "Kimi, make me a script to [remove/reencode audio tracks]." 😑