Hi Steve!
No experience with the 3 OSC synth just yet, but I've started playing around with the 3 Note Generator quite a bit, and it's opening up a whole new world for me. I've included a link at the bottom where I've setup snapshots to change note and octave values.
The parameters for the 3 OSC synth are:
Wave: Value from 0-10
Duty Cycle: %
Octave: -3 - +2
Frequency: +/- 12
Pan:
Level:
Filter Preset: 1-4
FM 3 > 1: 0-10
Low Cut:
High Cut:
Level
The first section is parameters that you can change for each OSC, and the second section is overall. The 3 Note Generator and 4 OSC Generator have more traditional wave shapes like saw up, saw down, triangle, sine, and square. The primary difference seems to be the extra oscillator and the way you choose notes. On the 3 note, it's octave/note, and the 4 is frequency based.
Let me know if you have any other questions.
https://soundcloud.com/daniel-berry-992559561/pads