Was having a thought the other day about an older conversation here about min-maxing, and I thought about non-piercing weapons again and thought a slight rules addendum might be in order...

Non-Peircing (NPr) weapons...
... (add to end of section, or before last paragraph; alternatively this could be reworded and placed in 4.3 The Impact Roll)
Against a target without shields (either by design or as the result of damage), treat the target as having a shield rating of one (1).

I think this closes a tiny loophole that allows some min-maxing to be exploited. I mean, really, what's the penalty (size and cost wise) if you're facing an opponent without a shield rating; NPr suddenly becomes extra SUs (a benefit) with no associated penalty (third paragraph of 4.3 says that with no or zero rating, no IMP roll is made).