VERY interesting find. You've got to hand it to E-H for their innovative and forward thinking devices. Even the build quality is miles ahead of where they started, Since my last post on this thread, I've actually breadboarded a rough prototype, and cobbled together a MIDI note sequencer with an event processor as an alternative. But this 8 Step Program has real possibilities at a reasonable price point, Plus it's transferrable to anything with a CV / expression pedal input.
It might be tricky to lock in the exact values for arpeggios. The Eventide inputs work on a 0-3VDC range, and I'm not sure what the Electro-Harmonix outputs. 0-5V or 0-10V would be more common, I would think. I already have about 75% of the PitchFactor algorithms mapped out for MIDI CC values. But that's 0-127, with some of the pitch parameters mapped on a log curve.
The expression pedal input would be 0-100 (on a good day).
Thank you for the food for thought, BarneyBrown. It seems like some kind of formula could be worked out to nail down the pitch values via expression pedal input (once all of the tools are in place). Trial-and-error is always an option. I tried that at first with MIDI CCs and the PitchFactor, but found it more useful to have a complete chart in place. All of the grunt work is done, and then it's just plugging in the correct values for the musical phrase that you have in mind.