Don't want to highjack your thread, Badchef, but no discussion of triangle thingies can be complete without a mention of SCUM's brilliant adjustable-in-the-hammock underquilt suspension design:
It uses cordage, four prussik knots on the ridge line for adjustability, and mini carabiners all in place of material, shock cord and cord locks of the triangle thingies. Just my opinion, but I think it works great, is infinitely adjustable from the hammock and saves weight. Just thought you might have missed this when Scum first posted. Good luck!