I've used the spray rustoleum on solartex. This is the caustic stuff that has tolulene in it. It stayed flexible on my plane. Occasionally you have to reshrink coverings here due to pretty extreme summer heat. To reshrink I place a white T-shirt type material over the wrinkle. Then use an iron to shrink the wrinkle but dont move the cloth, just the iron. The paint stays pliable and reshrinks without cracking. This was NOT on koveral and dope. Never tried that.
Edwin