I tried out these cleats this weekend on a Hennessy Hyperlight and my friend tried them on his Asym Deluxe. Neither of us hit the ground and I didn't have to fiddle with it at all. Worked well. Thanks for the tip and for all the testing. Knowing to tie a knot at the end to keep the cleat from twisting out helped as well.
I was reluctant to modify my hammock to use the rings. This is an easy, cheap, and effective substitute.
I'll be picking up a second set for my daughter's hammock.