I looked for a while for a method to batch demux or batch cut/join files in TMPGenc. I'm not a fan of text-based methods (like mpgtx).

This is a real forehead slapper too...

OPEN MULTIPLE INSTANCES OF TMPGENC AT THE SAME TIME!

It was that easy. The system slowdown isn't too bad, and you would have walked away anyhow since you were looking for a long-term demux method.

Open another TMPGenc session by opening the program again. Then setup your demux or cut/join operation and run it. Open another session and do the same thing. You can setup as many of them as your system will handle. Then walk away.