When it comes to the legal niceties - and I know we're deviating from the subject here - but the fact that a part is proofed will never override the simple FACT in law that it is not a load or pressure bearing part. It is called an 'irrefutable point of law' that can be proven. Like , say, christmas day falls on 25th December or the top traffic light colour is red. The rifle will fire and stay locked without the carrier. Try it with some blanks + BFA and see.......... If it were so, then a Bren piston post would be proofed. I appreciate that no one is game to take 'them' on in order to prove the point but.........
In fact a flash eliminator is more pressure bearing than the BBCarrier. That's why they split! I'd say that Christmas day is more pressure bearing too. Just joking!