Here are some pics of a JRB tarp plus GC pull outs providing lots of room over a JRB BMBH:
In this pic, I am using a pull out on the rt side ( small dark circle is Grip Clip ) on the left no tie out, "doors" closed.
Again, doors closed:
With all the room this gave me, you can see why it made me wonder if I could have squeaked by using them on the MC Dlx. EDIT: still, I doubt I ever could have closed the ends down like that without the rectangular shape of the JRB, even with pull outs. The Hex cut on the ends of the MCD would have made that difficult.