I would like to get the Mx51 surround sound software. I am not sure way you don't here more about them either, but I did an intense software search for other dts mixer and encoding software and came up with nothing other than minnetonka. I thought for sure professional surround sound audio recording software would appear somewhere, maybe protools has plugins for surround. And I did find dedicated outboard gear that "Hollywood" probably uses.
So I don't know anything about just mtracks, but that surround software looks killer!!