suction cups at high altitude are not a good idea. Loss of outside pressure as you gain altitude means suction force drops dramatically. Also rubber will stiffen in the lower temperatures making it easy to break suction with wind vibration, etc. The last thing you want is a camera flying over the canopy and hitting the tail feathers or pitot tube

Better to use a plate duct taped to the wing with a standard swivel mount, or gopro type mounts.