Overhead cover is anything a Grunt can come up with. So I find it deeply disturbing that modern day troops are so far removed from good "bushcraft" that a perfectly good tarp/shelter half would go unused. I used to be amazed at what supposedly uneducated, unsophisticated, and unmotivated troops could get up to. Nowadays that kind of hillbilly engineering seems all but lost.
Any kind of overhead cover, in it's simplest form, is merely a rectangle-shaped piece of material. Now you can gussie that up with all manner of things, and charge a shit-load of money for it, but my question is why? As a confirmed gear queer, with 30+ years of tom-foolery I have noticed a few things about this stuff. First is why the fuck can't the military field a simple overhead cover for the troops. That would take days to answer so let's move on. Secondly, proceed with caution when looking at what all these supposed SME's are doing in civvy street. There are multiple reasons for why guys come up with the shit they do. As a nitwit who has set out to improve my kit, I have sat enthralled by the Good Idea Fairey, making all manner of things. And here's the rub. Designing and testing shit, when you are warm, dry, well fed, and of sound mind and body bears very little resemblance to actual field conditions. All these little geniuses out there, with their ultra-lite kit, in east bumfuck Montana, are under ideal field conditions. Even when they think they're not. You have to take a lot of that shit with a grain of salt. Third-ely, I think a lot of these guys are just coming up with shit to get attention, as in look how clever I am, rather than looking for some kind of practical solution.
To the OP, if we take the modern shelter half, you can take a very simple concept, as in any scrounged cover, and turn it into some kind of science project, with special materials, and all sorts of features. Seriously? There are nomadic tribes that have erected this kind of cover for centuries, with whatever materials are at hand, and they would be looking at you like what the fuck, in the appropriate foreign tongue.
And perhaps therein lies the answer. Simple folk that live close to the land have this shit all dialed in. People from the info age, not so much. The farther out we get into all this hi-tech, the stupider we get with the basics of surviving and thriving in meatspace.
Editorial aside, USMC overhead cover, perhaps Army overhead cover (if OCP), the Brit Basha in MTP, various commercial ponchos, and any tarp-like object not nailed down would make a good piece of cover. Snaps are appallingly simple to add, even in the field, so making all manner of hooches, for various apps, is fairly simple. What's missing is the (good, old fashioned) improvisation needed to make it happen.