When syncing VCO1 to VCO2, VCO2 doesn't have to be playing the same note as VCO1- you can split them up by using Duo Split mode, by assigning VCO2 to the Ladder filter, but turning it down, so it is just a "ghost" vco that can only be heard, by what it is doing to VCO1. Play different things on each half of the keyboard, like droning the root note of a chord on the left hand (VCO2, the ghost). It can sound nice to mix in some of VCO3 with VCO1, too, to impart more of a solid note to VCO1, which just kind of changes tone of what you do with your left hand, in a melodic way.
Here's a preset example (with some tweaks on the macro knobs). Uses the 2.0 firmware to use a bunch of modulation slots, and modulating the matrix connections. The mod wheel fades between PWM square wave and Metalized triangle wave, Macro 1 does the regen on the chorus (long enough to be a slapback) for a verb feel, Macro 2 changes the pich of VCO3 (the normal sounding oscillator) two octaves, Macro 3 turns the filter cutoff down, but the envelope amount up, to darken the decay of the notes, and Macro 4 brings in tremolo/filter vibrato.
