ike... the deletion of the prusik is for the hammock UCR.
I dont think you will be pleased with the guy line UCR without some sort of tensioning mechanism. IN order for the UCR to work, there needs to be tension on the constrictor. I dont think you can achieve that in a tarp tie out simply by tightening the UCR. If the tarp had enough give, it might be possible... but I dont think even a nylon tarp has enough give.