I'm using the 8 Step Program with the PitchFactor. It's the most versatile stompbox pedal accessory that I've ever used. It can control anything that an expression pedal can (which is nearly any 'Factor parameter).
And every 8 Step Program parameter can be controlled over MIDI. There are an astounding number of ways to use it. You'll find that there will be a way to do most anything you can imagine using an 8 Step Program with a ModFactor.
I have created new effects in the PitchFactor that would be impossible without 8 Step control. It's like building your own modifications to the 'Factor algorithms. The key is to just dive in and learn how both pedals work together as a unit.