Unacceptable: tubular upper control arms with no bump stop pads.

I think so too. I’ve bought stuff from PST and been happy with it so this is probably an isolated issue. The adjustable strut rods Rich installed fit great and allowed us to increase caster to an acceptable amount.
Maybe the UCA was jigged and welded by a trainee or a guy working his last day!
We all want definitive evidence when trying to diagnose and fix a problem. For this issue, when the stock arms allowed nearly identical settings from side to side AND the aftermarket parts were miles apart, I dont see how the blame could be anywhere else.
Just be warned. Adjustable strut rods are not meant as a caster adjustment. All they are meant to do is get the LCA in the best position for good, smooth travel through its range of motion and that's all. You can end up putting the LCA bushings in a bind if you try and use the adjustable strut rods for additional caster adjustment. Just some friendly advice.