One of the boys in our troop recently made a cuben fiber pack and I am currently working on my first pack (cuben with carbon stays). With that said, I think it will be hard to muster interest. I did ask my son, avid scout and backpacker, and he said he would love to have a lightweight cuben pack. He may even learn to sew to have one. FYI, if you do go down this path: the following is a great starting point www.mountainultralight.com.
I like what William's troop is doing in buying packs for the troop that scouts can use. This serves several purposes. For new scouts they can try their first couple of backpacks with a lower equipment hurdle. It also provides a lightweight solution for the troop on longer backpacks. I'd rather see something like a Golite JAM at the recent $69 price and made of durable dyneema, yet only 2lbs versus 5lbs per above.
BSA preaches 20-25% of body weight for loaded packs, but I see this constantly violated. This really bothers me, since we don't see kid's suffering from being cold or dirty. Rather, we see them struggle with the weight and not enjoy backpacking. Even worse we can look around at adult scouts and see a myriad of knee, hip and back problems. All of these can be caused by overloading. Having the troop take control of a few big items, pack and tent specifically, can go a long way in solving the "go heavy" problem.