Some years ago now, I made a "sleeve" out of a poncho liner, for my hammock. I sewed a long (110") zipper to a short side, and down the long side. So basically a poncho liner turned into a sleeping bag liner now.
The way I use it is, I sleeve my hammock with it. I pull my hammock though it - end to end. Yes, a little hammock comes out of each end. The end with the zipper is zipped up (closed) and the other is open. It's more than big enough to fully cover me if needed, and that's with me on my side - with legs pulled up a little / or fully stretched out. It easily slides down if I want, for getting in/out, or temp regulating (or up over my head)
What I've found is that it creates a nice "little/micro climate area" for me when I'm in my hammock. I've used it, along with a bag in my hammock, down to some pretty cold temps (sub-zero F), in the wind, and been quite warm and comfy (mid 70's to 80's F inside the sleepingbag, when single digits - not counting windchill - outside). It does a rite handy job of blocking the wind, or keeping the wind from robbing the heat off of me while I'm in the hammock. It isn't waterproof in any way, but that's what I use my tarp for (if it's raining).
The woobie sleeve just blocks, or deflects, the wind. In the summer, it's all I use. In the cooler, to cold months, I use it, in tandem with a sleeping bag in my hammock.
I doesn't make noise in the wind, and won't blow away either. I don't know that it would qualify for ultra-light, but it works well and is what I had on hand when I thought of it.
Maybe worth a try?