John, nice work on your article and spreadsheet, it's obvious you put a lot of time and energy into it.
I echo Bob's concerns over having shelters set up vs. actually living in them. Wear and tear is being removed as a variable, and I would say that is one of the most important (if not the most important) variable for a good shelter.
Next, there is a sub 20oz shelter that you ought to consider in your article/spreadsheet that is missing: the hobo tent. Especially if you are taking cost into account!
My hobo tent is comprised of clear plastic from a big roll I bought from a hardware store. It is a 2.5m x 2m rectangle. The entire roll cost me 150 SEK (about 22 USD), and is 20m total and 2m wide; which means 2m costs 15 SEK (2.20 USD), but my shelter is half a meter longer, so let's round it up to say 20 SEK (2.90 USD).
I tie a plastic rope between two trees to hold the shelter up. I can't remember how much I paid for the rope, but it was not much. I know that 10m of heavier plastic rope costs 20 SEK at IKEA, so we could use that as a similar price. Then there are two small plastic clips (similar to the kind used to close off potato chip bags) to hold the plastic sheet to the rope, which are also next to nothing as far as cost, I think 2 SEK would be a high estimate, as they come in bags of like 20 for a low cost which I also can't remember exactly.
For a ground cover I use a garbage bag that is cut in half to create a big rectangle that fits my frame perfectly, leaving some space on each end when I lay in the middle. The garbage bag is for toughness and goes on the bottom, on the top I have duct taped a rectangle of space blanket to fit the garbage bag. The garbage bag cost me about 2 SEK, and the space blanket was 30 SEK.
That's the entire shelter, and if my math is right, it costs about 64 SEK (9.30 USD). It weighs 338g. You could save weight by only using a space blanket as your ground cover, but where I hike/camp there are lots of pine needles, sticks, etc., so I would not opt for that. Or replace it with Tyvek or Cuben.
It's not fully enclosed, but you could add several different options to make it so. I own both a Ti Goat Ptarm bivy (200g) and a Zpacks Solo bug tent (193g), and when I add them to my hobo tent it's 538g/531g, which makes it under 20oz. And you could tweak this set up with a lighter bivy or bug tent.
For the record, I have used my current hobo tent 4 or 5 times this year (all far off-trail I might add), and each of those times I got rain and/or snow and was dry as a bone. I have used the same sheet of plastic, same plastic rope (about 7m of it, 30g), same clips, and same ground cover. There is some mild wear and tear, but I plan on using this same set up more in the future. And if it needs repairs, all I need to do is add a bit of tape. Oh, and I am 6 foot tall and weigh about 180lbs, and yes if pitched correctly I am able to sit up in this shelter (though my head does rub on the top some). I am also able to clip my flashlight to the rope at night, and you could clip a bug shelter to the rope the same way. Also for the record, I have yet to try the Zpacks bug tent with the hobo tent, just my bivy, but I plan on trying the bug net out in the future during bug season and don't see why it would not work.
I firmly believe that one could use the hobo tent on thru hikes in most areas. All you need is to have two trees around to tie your rope to. There are people that have done thru hikes of AT, for example, that I know of, using a hammock as shelter. Worse case scenario, the shelter gets badly damaged beyond what duct tape can fix. No big deal, just have a friend or family member mail you another one that you could have made and packed and ready to go just in case. And would be very surprised if you could beat the price of two hobo tents compared to any other shelter!
I hope this is helpful. :)