I hate to rain on your parade, but my XP60 does not exhibit this anomaly, i.e., it does not double any controller data on any channel or track (including aftertouch), nor have I ever experienced timing glitches or problems, and many of my sequences are nothing if not dense. Sorry.

Yes, I'm familiar with the sequencer, microscope mode, etc.; I've been using these sequencers since 1993 (also have a JV1000). I can't get my XP60 to duplicate the controller doubling.

I'm certainly not saying your units don't act the way you describe; I'm just saying mine have not exhibited any of these problems (I also had the XP50 before the XP60).