As I said, I’m not really familiar enough with the VW stuff to really comment on what does or doesn’t work on a VW, there could be a way to accomplish preload in that system I’m not aware of. Probably shouldn’t have speculated.
On a Mopar suspension, if the control arms come off the bump stops the load on the bars is just the weight of the car and the spring rate is the same, so only the ride height is effected. I’ve clocked the bars on a Mopar a flat off, it doesn’t work the way the that’s described by the “kid on Facebook”.
Although arguing with him is probably also a waste of time, since he doesn’t seem to have a good grasp on how the suspension actually functions.