I saw a VFG which mounted directly to the stock forearm. Forget who makes it though.
FWIW, I also learned to rest the forearm on my supporting hand, but I was most comfortable with gripping the magwell. Someone talked me into installing a rail system with a VFG, at no cost to me, stating that gripping the magwell inadvertantly leads to magazine malfunctions when you wind up gripping the magazine as well. Well, never had it happen, but as I said, tried the conversion at no cost and wound up liking it. It also lets me get the stock tight into my shoulder in CQB. Someone here mentioned biomechanicals. Well, it seems like a more natural position for my hand than supporting the handguard.