You are way too patient!! I would have cut it all out....seems easier to me and I'm lazy. I've only seen 3/4 used, in coosa that is a very small difference in weight. Only 17 pounds for a 4x8 sheet. However with 1708 on the top and bottom of 1/2 coosa there is no reason to think it would not be strong enough. I would for sure use backing plates for the CC and leaning post bolts/screws for 1/2.
http://coosacomposites.com/pdfs/coosa_weightchart.pdf