To make the cables, you just put a resistor inline? Is it that simple? And this may be a silly question, but if the stompboxes just want a 3V max, why not set the toe value of the channel to 3000 or so? Doesn't that restrict the range to 0-3V? 

My setup is the MP201 going to a MIDISport 2×2, (to In A). Out A then goes to the TimeFactor. The TF is set up as I described, while the MP201 is set to expression mode, MIDI only, Ch2, CC25. This works reasonably well, although as I said the TF does not go from 0-100 when I sweep. 

If I switch the MIDISport into merge mode, the TF seems to get few if any messages — it'll show occasional values but mostly not change at all as the pedal sweeps. But in all cases, the MIDISport is outputting a steady stream of correct CC messages. 

Thanks for your help.