Lots of good info here for you, I havent read it all , but this is what I had (if the image downloads.Maybe it wont. Use your imagination!).
Its like what you propose. Its a homemade bug bivvy made with an ultralight silnylon floor and a midge netting tube. No zips, just a very large drawcorded hole to get in. As you see it hangs up, a wire hoop isnt needed.
I needed this for sleeping out under my poncho, which I did on 3 nights, doing the Primitivo. I also slept in it in albergues to assuage my not-taking-bugs-home-at-any-cost pessimism. I merely slept in lower bunks and hooked it up onto to the slats above me, along with socks, etc..
Nobody objected or even commented, The Camino is full of nutters like us, so go ahead.
Of course it got too hot under it sometimes, but then I just used it like a liner, unhooked. It was treated with permethrin,
When I got home it went in the freezer for a week along with everything else. I didnt want to go through what a chap I knew went through...months of misery surrounded by plastic bags as "experts" failed to decontaminate his young family's home.
People will accuse us of being paranoid (same as with following covid advice) but we can accuse them of being lazy , cant we ?