I have considered (been obsessed with) for the last couple of hours. At first I thought that pointing out that an extra pound or two wouldin't kill you and point out to several tutorials on making sub one pound hammock systems from someone who has put a lot of thought into it...
Here
https://www.hammockforums.net/forum/showthread.php?20614-Full-hammock-Setup-for-13-oz-and-360
Here
https://www.hammockforums.net/forum/showthread.php?20115-Sub-1-Pound-Hammock-Rig
And here
https://www.hammockforums.net/forum/showthread.php?43521-Ghost-Hammock-DIY-ultralight-hammock
I have a 2 pound custom hammock that can easily with a couple of knots double as a bug bivy in my Megatarp. When I bought this hammock it was before the maker hit his stride and came out with lighter, just as capable hammocks. My current hammock with some options that he now offers would weigh about 22oz, and he has several that go down to 12 oz. The super light weight hammocks with a bug sock could do double duty indeed.
But then re-reading some of your concepts, I have a couple of different ideas.
Since everything above violates you initial premise, a different direction is necessary.
I don't know how DWR and Cuben fair getting blood all over them, and then being cleaned. Every solution presented above will also cost you into the hundreds of dollars for a potential multitasker that will do hammocking pretty well, and everything else so so. I started thinking the other way. Light weigh, disposable, and does a few things well.
Choose your material. Ripstop (do some reasearch on the light backpacking groups. Depending on your size you may have to pick a specific weight) is the go to, but thinking outside the box tyvek and cuben might be possible. If you are on the small side they may work. There are reports on line of guys 150-170 using cuben and tyvek for a hammock. Tyvek is much cheaper, and still 1.6 oz/sq yard. When either fail they fail big. Maybe a few strips of tape on the outside of either to help distribute the load. There are mentions of cuben hammocks, but the guy developing them decided not to sell them commercially because of how delicate they ended up being. I am almost willing to try tyvek.
Make one of these:
https://www.hammockforums.net/forum/showthread.php?15205-Instruction-Gathered-End-Hammock
When you get an animal down, cut the whipping off the end, remove the ridgeline and the whoopies, and lay it out and you have a ground cloth, or windblock/sunshade, depending on how you feel about putting meat on your hammock material.
I just had a brainstorm and went to my closet and got a M1966 jungle hammock that a friend had given me. The suspension was inelegent, and confusing, so I stripped it out. It weighs 13.5 ounces without the suspension. It is 32x95 inches. It can be had online for about $20 bucks. It could serve as a pattern, and judging by how the suspension is attached you would only need tree straps (about 2oz) and 2 whoopie slings that could be quickly removed would only add 42g. For what you suggested, I would use it as is, or use it as a pattern for lighter weight nylon or tyvek.
The drawbacks and advantages of the materials available to use may just want you to buy a 7 ounce Nano 7, and a couple three ounces for a mylar space blanet for a gound cloth and remind yourself that you are out there for your enjoyment, and 3/4 pound for this setup, as something that you want shouldn't be a deal breaker. Your back, your gear, justify what you want. There is a huge difference between being disciplined in you packing to save weight and taking along an extra pound or so in a comfort item you desire.
pat
