Got it covered, Built one myself, only non standard part required was an 11 inch gas tube custom made by White Oak Armament. Put the barrel in an Aero receiver, used the Sig bolt but headspaced it with two other DPMS platform bolts, functions with all. I use the Sig 716 bolt catch in all my builds now, strongest shape going, worked in every build I tried it in, $6.99 at CDNN.
That’s basically what I’m seeing too.
Only thing that’s really changed is the fact that they are “clarifying” lol, the fact that they don’t consider a side-folder on a pistol to be part of its overall length when determining if it is a pistol or not…and any brace that extends past the back of the buffer tube is not counted for length either.
Pistol = no vertical foregrip (any length).
AOW = less than 26” + vertical foregrip.