Pinching of the boot is a serious design flaw by Ineos/Dana/Magna and should have been easily identified during development. An engineering 101 screw up of the highest order. Excessive flexing of the boot while also unacceptable at least would have been less easy to identify as an problem. Dana or Magna had to raise this as an issue and Ineos chose to do nothing and proceed with production anyway.100% gets pinched. The rubber gets extruded by the pressure and thins out. Eventually it develops a tear which centrifugal force takes advantage of and finishes the boot off.
This happens on stock or lifted trucks. Just happens faster on lifted because you live closer to the extrusion point.