I have tracked my car both ways. The car is MUCH more stable above 120ish with the 99 wing at full rake and the gtc front bumper, no other changes. My alignment specs are similiar to pettits long track setup.

there was an sae paper about the changes in the 99 rx7, and theres a little blurb about the % of rear downforce vs front for each position of the wing.

full rake gave some front end lift...

maybe the gtc bumper helps balance it out? I'm no engineer or pro driver, but I would think as rear downforce increases the front would have a tendency to lift?