You've done an incredible job Rusty. Sorry, another image dump for the final feedback.
It would be great if you could post a flat side and front view (as opposed to the perspective or 3/4 views) just to do a final check on everything.
Body rounding
The edges on the body overall still look a bit too sharp. Just a slight amount more rounding on all edges would be good. Here's a couple of ref pics to show overall edges.
Side channels
Red arrows show the channels I mean, that run top and bottom of the torso on both sides. The two side channels currently seem a bit too shallow and also possibly not wide enough where they touch the edge of the body (almost like it needs to be wider at the edges before they begin tapering toward the middle of the torso.)
If you look at the pic just above (the two Hoth gonks, which are same mold as sandcrawler gonk) you can see on the top face of that front gonk just how deep these channels cut into the body. On the full size droid, it looks like it was 1 1/2" or 2" deep into the body, which would be like 1/4" deep in 1/6 scale.
Missing "exhausts" detail on rear (plus tweaks to waist and rear ports)
There is one more detail that is missing on the rear - three exhaust ports (marked in red.) Seems like the HT is pretty close and there doesn't seem to be any more reference, though you can see the top of it on the previously posted pics.
Also, minor note but I did notice that it seems like the lower edge/border strip on the "waist belt" is thicker than the top edge/border strip (strips marked in green.)
Also, the two vertical rectangular ports you have already sculpted on the upper rear look like they need to be made deeper, almost double the depth they are currently (see the HT depth in pic below.)
Overall height of figure
Some 1/6 gonks I've seen seem too tall. There aren't a lot of great humans-next-to-gonks ref pics, but I found a couple that seem to show the figure should come up to around mid/top of the belly on a 6' person (the 3PO suit is just under 6') These two pics have humans in the same plane as the gonk.
According to my Tama and Sideshow 3POs, that would make the gonk just under 8" - around 7 3/4" - in overall height.