just a thought about the abrasion..
Just a thought here about the issue of abrasion you had on the converted cuben tarp hammock..
You said it was double layer right? Wouldn't any dirt/grit/sand that got in between the layers be a big source of abrasion under the stress of laying in it? Grit sandwiched between two taunt layers of cuben would wreak havoc on it if you moved around.
That would be my guess. I'm no hammock expert, but I wouldn't think making a double layer cuben hammock would be a good idea unless it was completely sealed.