I had thought about this the second I saw it. One of the annoying things about the WBBB shelf is the tie out doesn't always work right with a low tarp or there is also the trip line inside the tarp.
I simply added a loop to my COTPO and tied off to it. Using a clipped mitten hook makes this a quick set up and removal.
For pics and more I have a write up on the Dutchware forum at