I mean, the only way to be POSITIVE is to torque them on the ground at ride height. But even then, if the ride height settles out or changes any you have to repeat the process if you want the bushings to be perfectly neutral at ride height.
Realistically, as long as the LCA is at the same angle it shouldn't matter if it's in the air or on the ground, and as long as you're close it should be fine. When you're driving the suspension is constantly moving in one direction or the other and the bushing is flexing back and forth. As long as the bushing isn't flexed past the point where it tears it will be fine. And that shouldn't happen as long as the LCA is reasonably in the middle of its travel when the pivots are tightened.
You know the factory was not this precise on the assembly line.
