When I waxed my A128 a month or so ago, I crawled around on the roof sections (which were in the down position) on my hands and knees for a half hour or so, applying and buffing. There was no detectable bending and no scary noises were heard at any time. I weigh about 155, so if it'll hold me with no complaint, it should hold a Kayak.
It's never too late to have a happy childhood!
Lee, WU0V, and Courtenay, N0ZDT
2011 Rockwood A128
2000 Silverado 1500 pickup
60W solar system
2000W inverter generator