It sounds like you have the flat baseplates, and the officer had the extended baseplates.
However, I am not aware of HK making any "change", as they are just simply two different types of baseplates and both have been available since before the CBP contract existed.
I have never had a baseplate crack and I am usually dropping my magazines directly onto a concrete floor, but I can also see how the rubber lip on the extended plates would cushion some of the shock.
"Don't hit at all if it is honorably possible to avoid hitting; but never hit soft." ~ Theodore Roosevelt