I have seen 2 very different reactions to rudder input in a K/E situation. In my H9 Twist, the plane rolls towards the top of the wing and down elevator cures the problem. In my GP Cap 40, the opposite occurs. The plane rolls hugely towards the bottom of the wing and requires opposite aileron(opposite to rudder) and up elevator to cure the problem. Is it the Twists lack of any dihedral that makes the difference?

If you do a search in this forum, you'll find a huge amount of discussion on this subject, links, etc.. It's one of those things that keeps resurfacing here, (with good reason) and so we've talked about it a lot.

The more you flight trim new airplanes you'll find it's a combination of a
lot of things that affect this , dihedral, moments, rudder hinge angle, incidence
angles, CG , thrust lines, wing and stab placement, etc.
A lot of times when you get an airplane that flys true in knife edge it's just dumb luck.

tommy s