The plastic doesn't really have anything to do with the support of the casing and the only real risk is working it so thin you could get a minor crack or being able to pinch the mag with a strong grip. So...no, it won't make a Kb more likely.
I like a reworked grip. A worked grip can be custom tailored in a way that no manufacturer can match. This isn't a Glock, but the same thing applies....(and it looks nicer, anyhow)
Lycanaestheticlessonthrope