The manual for the Eclipse specifically mentions using CV inputs for the expression pedals. And based on what we're talking about with the TimeFactor, if you deliver between 0 and 5V on the return, it should treat that no differently than a regular expression pedal. Either way, it sends out 5V on the source and gets back 0-5V on the return. For the Eclipse, the ring is the source and the tip is the return.
Also, I found this out by accident, but the MP201 expression pedal alters parameters too, very quickly. I use that to set values like toe/heel roughly, then use the knob to get the exact number I want.