As you may know before I'd made a clipping style preamp for the original release which was very popular. I'm just working on improving that. Been looking deep into harmonics too!
Basically when using the eq you'll insert the low band and a preamp as your base presets this to make the overall correct knobs at 0 coloration. Then add high boost and attenuate as the isolated bands over the top, the idea is the phase transient responce stays true as possible to the hardware. So all stacked up with everything on and knobs at 0 you'll have around 10 degrees out of phase at 10khz rather than say 40 degrees.