I ran into this issue (roll center going too low) with my Focus track car. I solved it by making the inner pick-up points of the LCA adjustable - slugs in front and spacers in the rear. I was able to keep the roll center at .75 inch above ground with full compression. Without the modifications it was almost 2 inches below ground level. In addition, I was able to angle the control arm up in the rear which gave me more caster gain with suspension travel.
Pappy