I’ve been using the PO Modular along with the Roland A-01 with pretty good success. I use passive splitters so I can deliver the pitch CV to all three key inputs on the oscillators, and then plug the gate into the trig input on the envelope and run the envelope into the the VCA. Works like a charm and sounds great. I also take the mixer output and send it to the filter so all three oscillators get filtered, which is cool. I haven’t tried using the sequencer yet on the A-01, but I imagine it should work fine with the same setup. Now if I could just get rid of that background whine!
This is my first foray into modular synthesis, and if you’re willing to put in the elbow grease to put it together and then learn the little oddities (i.e., the PW knob), you can get lots of really great, entertaining sounds, from straight synth line type stuff to total, beautiful chaos. If I had a wish list, number one would be a different (better?) filter, number two would be a fine tune knob on each oscillator (they’re almost impossible to tune precisely because when you take your hand off the knob it moves slightly but unpredictably), and of course number three would be the power/whine situation, but perhaps getting the actual TE PSU will fix that. I’m currently using a third party PSU, and the whine is quite distinct.