Yep on question 1. Both areas were creased.Can we assume the crease has crossed into the area without primer? Since this paint is lacquer based, it will become brittle over time so it could crack more easily after it cures completely - perhaps after a couple weeks or more. Acrylic enamel paint might be less prone to cracking.
Cracking is one issue but I think the real concern is about overall adhesion and that's where the promoter should be helpful. By chance, did you prep the lexan - maybe with a Scotchbrite pad?
Yep on question 2. I prepped a portion of the lexan with 3m 3000 trizact. No part of the test, primed, scuffed or straight to lexan showed problems with adhesion.
I have found 3m 3000 trizact barely creates a haze with virtually no scratching and no evidence on the final painted finish.
I will recheck for cracking after thorough cure.
Chuck