If its so easily solvable then why has AGD not started shipping markes with it 'solved' from the factory.
I certainly agree that there are 'mag configurations out there which minimize (or eliminate) the harmful effects of blowback, everything from a powerfeed to the slightly longer bolt (did this help?) are attempts to reduce or eliminate the harmful effects.
The fact remains that most mags have some blowback and this causes FTF problems, and is _the_ reason vertical feed 'mags have such a stigma attached to them.
Yes I know there are these legendary (Manike owns one) vertical feed 'mags that work perfectly, but the fact remains that they are not widespread.