I know aviation has to because the Polyester will not hold up to the hydraulic fluid but today on out side of plane I have no clue if they even use fiberglass any more.
I would like to know about about the people building these 32 and 34 ford body's and others. Polyester being so brittle there would be an advantage.
Speedboats? last i knew (years ago) 80mph was the cut off for a polyester as well as most paints.
I think if you call the guy repairing holes in the big boats, he not using the polyester for that application, The adhesion and strength is just not there when your 20 miles out.