When I made one, I neglected to think about using a mattress on it. Or a plywood insert.
In sampling it before we went to RDV, we laid on it first to see how it was.
Just sleeping on the ropes, there was a real tendency for both of us to roll towards the middle.
Not conducive to a good night's sleep, but OK for other things I would imagine.
I just considered that a lesson in learning what you are doing before you do it.

Well, shucks, I never said I was the brightest light in the house.
It was good to have all that rope, however. I guess I used the wood for other projects, but I sure don't recall what.
John