Sure, they will stone chip, but so does 2Pack.. even powdercoating.
Funnily, acrylic has more elasticity, so will craze less....
Point is, you need to be almost a seasoned spray paint professional to get decent results in 2Pack, it's vital to have safety gear and is in fact illegal in most states to spray it outside of a properly prepared extraction booth. You also should bake 2Pack to get the best results...
Acrylic, although predominantly used in the 70's and 80's on cars, has come a long way. The modern spray finishes benefit from formed metal that needs very little bogging to get dead flat and also electrostatically charged paint bonding mechanisms.. nothing like the old way of painting.
Least acrylic is cheap, safe and forgiving to paint with...