Since ATF has already said that braces are accessories and therefore not stocks (stocks are integral parts of the firearm “accessories) are not) I don’t think it matters how you hold the AOW. That’s getting squishy though into the area where caselaw and Precident starts to become a thing. A president that would favor us is the fact that putting two hands on a Glock 19 when you are firing it doesn’t make it into an AOW.
I think the tail hook is probably the most solid.