I've got to stay in my lane on this one. My live rear experience is pretty skinny. You're 100% correct about the RC movement with respect to the CG. I do remember that the fastest of the old Trans Am cars often used a Watts with the pivot on the bottom of the pumpkin & it swiveled about a vertical axis, which I thought was clever. When I asked about it (& remember, this was 25 years ago), the engineer said it was an effort to make the car as soft in roll as they could to improve traction at corner exits. As to what to actually use on an S197, @Fabman and @blacksheep-1 is who I would ask.