Garfield, I think we agree on this pretty much, I think you are right in that LilP should start more basic, if he wants a chord machine later on there are a few good ones. Study filters and when you find a filter you like, chances are Doepher is selling a clone of it for 80 euros. What I like about his rack is Plaits, I think he could have fun with that one. He seems to be going more west coast so additive may be his thing. Hysteria from Dreadbox is actually a very good oscillator, goes for a 100, has a quantizer, is additive in part, perfect for sync and stays in tune.

And so back to the polyphonic question and on a budget, Dreadbox has a very nice line which is not expensive https://www.dreadbox-fx.com/chromatic-modules/