"Are you sure you're checking this right?"

Well, I know I've never had timing problems, so that's not a matter of checking. I do stagger some events by 1, 2, 3, etc. ticks/clocks if a passage is particularly dense, but I've never done it because I've been prompted by timing delays. I just do it; always have (even on the JV1000, which has some massively dense sequences).

As for the controller doubling, I just went in and recorded about six measures on track one, channel one, just random doodling, pressing down for aftertouch, using pitchbend and modulation, leaning into aftertouch again to get plenty of events. Checked in the microscope: nothing but channel 1 data, everything I had played; nothing from channel 16.

"Maybe this is a US problem only?"

I'm in the US.

So now what? That's why I said that this thread has always puzzled me.