I think I found my solution here.
My problems are I always have trap wires tangled up, and I break cord pretty often pitchpoling and dragging myself along behind the boat. I like the idea of using the through tramp grommets, but there simply isn't enough cord in the stock system... and the double system sold by Hobie only corrects part of the problem....
So... Why not run each section of shock cord individually? Through the grommet in the tramp, to a microblock (old jib sheet blocks) at the corner casting and then to the casting on the same side... (or to the other side... whatever...) Skippers shock cord running aft first.. crew line headed for the bow first.
This keeps the system for one side entirely on the same side of the boat..
Keeps the blocks off the rails/out of the way of shockcord travel... and no drilling required to tie them up near the castings.. (if you didn't want to use the through tramp grommets a low friction ring like above could be tied to the Shroud and location could be adjustable... )
Nearly (not quite) doubles the amount of cord.. But leaves you carrying more shock cord in total than the hobie system.
While still requiring four blocks the shock cord on each usage is turning through the grommet and one block instead of the grommet and two blocks..
Should you break shock cord you only lose one trapeze handle on one side of the boat.
I'll get it built Thursday night and post some pictures.