It's been over a year since the canopy was finished - it was glued on the frame with Sikaflex, per many RV builders. But the lower trim pieces on either side of the canopy at the upper longerons were riveted on, with STAINLESS rivets, and they have stress cracked pretty badly. I'm not sure whether to leave them, in hopes they've relieved themselves, or stop drill every single one of them. ALUMINUM rivets should have been used in my view, as they take far less force to "pop", preferably in oversize holes. This would lead to less compressive stress, and allow the acrylic to move a little. Threaded fasteners, LOOSELY torqued, with nylocks, would have been another good choice. Keep Loctite away from acrylic, it will craze and crack it.