Not sure if this will work the way I want it to, but I just tossed the M2TS files for my preferred crawl and the rest of the movie and the DTS-HD tracks from Harmy’s 2.5 into TSMuxer. I’ll let you guys know if it worked in 20 minutes or so.
EDIT: no dice.
EDIT2: Just discovered the “join” function. Commencing attempt 2.
EDIT3: That worked just fine.
EDIT4: Ugh, still too big to fit on a disc. Looks like I’m waiting for the MKV after all.