I'm no expert but asked this question before to some pretty good paint guys and the response was "nothing, just get'er done". Interesting to see if anyone has anything to say about this. One painter I talked to about this recommended putting an "elasticizer" in the paint. I know you can get this from Dupont, but don't know if you can get it from PPG. The elasticizer prevented the paintjob from being brittle. My F-15 was painted with it and you can pop the sides of the fiberglass in with no effect on the paint.