I think entropy12 is saying the same thing as me. People can carry guns into any unsecured area. So how the guns get into that unsecured area is almost irrelevant.
I also do not support guns in carry-on bags, unless its carried by LE (of course).
I agree with you both there.
By process of elimination, the critical points you both touched on are already open.
No need to argue a point about another way to get a gun into them, since guns are already allowed in them.
Thanks for the additional note.