MKV Optimizer is a super handy tool to search & find all MKVs of a directory incl. its subfolders which, for example, have more than 1 audio track to batch-delete audio tracks of a specific language or Track ID.

Do you now of any tool which does the same for MP4s?

My workaround right now is:
- Windows Explorer: search & find all ".mp4"-files and drag & drop them into
- Advanced Renamer: batch-replaces the file name extensions "mp4" to "mkv"
- MKV Optimizer: batch-deletes all 2nd audio tracks
- Windows Explorer: search & find all ".mkv"-files and drag & drop them into
- Advanced Renamer: batch-replaces the file name extensions "mkv" back to "mp4"