[Dominik]

here is now my best guess:

to get the front roll center a little above ground I found a front upright that is 3/8" (to 3/4") longer between the center of the ball joints than the spacing of the upper and lower mounting points at the chassis.

to get the rear roll center higher above ground than the front, I design an upright which is 1 1/2" longer than the spacing of the mounting points at the chassis.
the wider track in the rear also moves the rear roll center slightly up.

I think it is a good start.

I am thinking about using two different mounting points on the rear upright, one higher than 1 1/2".
the wider track in the rear also moves the roll center slightly up.

a next chassis may feature two holes per wishbone to play a little more with the wishbone positions at the chassis.

keep well,

dom