hmmm, not sure about that...
Most of the time, we ended up running 3-hole pistons, with slightly heavier oil. Also removed the red foam piece from on-top of the shock, which helps reduce the pack and make the car smoother overall.
Raising the roll centres does work... but I personally never went above 1.5mm (and that was on a very quick track, with a 27t), but that did carry awesome corner speed.
Something else that was done as a general rule of thumb was white/blue springs, and no roll bars. Have a look here, if you haven't already for a number of setups that work well
THard 415 pages.
HiH
Ed