I'm in the same boat with you. I too have a scar heavy and wanted a KDG stock.

After reading a number of metal hinge plate threads I've decided to pass on any stock with a metal hinge.

I bought this gun based on its reliability and durability. I have no interest in mods that degrade either of those two things even a minuscule amount.

Personally I think the best policy is to own a second fn stock to have on hand if the original breaks in anyway. I also never open the stock with out fully depressing the button when locking it in place.

It's a great gun, the hinge plate is its weak point. Putting on an aluminum one actually causes worse problems long run. I'm in no way trying to jack up my receiver. I'd rather the stock be sacrificial.