The Tarp Flyz work a treat on guylines, I've done around 15 nights now with them.
I'm testing them alongside some nylon cleats (not the line locs).
FWIW, If I was using a tarp with only corner ties, the Flyz would be ideal IMO. With my 16 atachment points, they become a little tedious to release though.
If Dutch sees this thread, I reckon he could knock something up out of ally or ti, very similar to the Flyz that would be perfect.