Is soccer ball inflation and weight a safety issue?

There’s a remarkable difference between a soccer ball pumped up to FIFA’s maximum PSI (15.6) compared to the minimum (8.5), as you’ll clearly notice if side-by-side you squeeze, bounce or head balls inflated at each level. Why the range is so large remains a mystery to me, but a recent study  by Purdue University engineers suggests it worthwhile to further research the effect of ball pressure and ball weight on head injuries.