Hi Alex,

The roll tendency does not have any relation to the wing and stab incidences. This is related mostly to dihedral.

The common practice suggested by ZN is 0,25 to 0,4 degrees negative stab with respect to the wing.

You have pitch coupling on left KE to the belly and zero coupling on right KE.

Seems that your plane needs up elevator on left KE, if you either move your CG forward =>will need more UP elevator then, or decrease the stab incidence then you may correct this issue, but you will "damage" the right KE qualities. I face exactly the same issue on Integral and only solution found is 10% up elev mix on left KE. My stab is set at 0,4 degrees negative to the wing.

Nikos