A .22 slug traveling at 99fps is a pretty low standard for bulletproof material.
They definitely need to seek a remedy for stuff traveling in the 2700-3200fps range.
That they can't stop a .44 mag right out of the starting gate does not diminish this invention in any way. I think it is really a great find they have here. Think of the possibilities of other composite materials that can be made this way, other things that can be added to it, and other applications besides just bulletproofing. There is all kinds of medical uses for such a tough skin such as burn victims, hemophilia, sensitive skin diseases, extra layering for working in hazardous areas, frostbite prevention, clothing, housing materials, windows, rope, outerspace materials, reinforcing polymers for all types of uses, etc... the list goes on.
Plus it is a different way of manufacturing that can be looked into for other possibilities and applications.