As I understand it, the problem is in case expansion, not in the loads. the unsupported part of the case can expand, and when reloaded several times with the same or similar part expanding, that part is weakened. Eventually you'll get head separation, or a blowout when the weak area fails.
Personally, if I had a Glock, I think I'd buy once fired cases, load them once, and ditch them. It will still be cheaper, and not worth the risk of pushing those cases.