Honestly hate being the wet blanket as the AFG looks good and I'm a big proponent of featureless rifles.
Further clarifying the relationship of (c) and (d), since (c) comes before (d) and makes no mention of (d)'s definitions, it's not bound by (d). (sounds like Abbot/Costello "Who's on First?" right? LOL).
And since "grip" is an important element of (c), it greenlights the KAC handstop on a featureless build. Not only is it not used or marketed as any form of grip (nor can you even remotely hold the rifle with it in any form of a pistol style grasp), it's a sling mount too. There's your GTG item on a featureless build, that's very defensible in court.
The AFG...not so much.
"On bended knee is no way to be free." - Eddie Vedder, "Guaranteed"
"Let your gun therefore be the constant companion of your walks." -Thomas Jefferson, in a letter to his nephew Peter Carr dated August 19, 1785