Well, as long as you properly prepare the surface before painting it shouldnt chip. medium sanding, then light sanding, then clean with a tack cloth and primer it.
I believe the trim paint doesnt need a primer though. As long as you dont spray a heavy first coat (just like a mist) it should be fine. On another car, I painted all trim this way and it was fine. I did about 3 mist coats, then a regular thicker coat. If your STILL worried about chipping or peeling, you can clearcoat it and wrap it around the backside, but then it'll have a gloss to it