[Blas]

You would want the backside of the quick-jack to be perpendicular to the ground and you would need to visualize a round bar inserted into slots between the two jacks to set the minimum projection from the bodywork. This bar must adequately clear any body work. As to actual distance from body, minimal with an eye on aesthetically pleasing I would think. But be advised, on the Superformance, the quick-jacks are not functional jacking points. You will crack the fiberglass when they flex if you try to use them to lift car. I really don’t think there is any “correct” distance. The angle they sit at seems to be more visually important.
After replacing the bumpers with the jacks, keep a running list of how many times you mangle your shins with them. I think I am up to 5 times on both legs so far....
Blas