Haven't spent much time on this since I decided to just go with the monster bimini, but it's been floating around back there in the dark crevices since. The ski rope shown is at like the worst possible geometry (sixty foot rope with handle at water level and boat at zero nose-up attitude). Realistically, you'd never have a loaded line at that angle because the boat pitches up when you start to pull, etc. So the jinge would be there in case there was load applied. If it were smaller and under the tower top it would definitely not need the hinge, and there are other options there.
One cool thing is shown in the top pic - with the hinged one, or even a solid one, it'd be cool to have it dialed in such that it comes down easily and mounts in a lowered position for trailering. Agai, a smaller one wouldn't need to come down, but the large one would and if place right, could really clean up the aerodynamics of the trailer for those long hauls. Oh yeah, the rest of you guys live next to lakes.....
I just think having that thing color-keyed and logo'd would be so friggin cool. There's still some challenges in terms of getting it light enough for our small tower and yet strong enough to deal with maybe like 60 MPH gusts.
I had thought pretty much like under 1/4" glass with some core material sandwiched in a arrangement to stiffen it. For the big spenders, use a single layer of carbon underneath wiith a clear finish.