Paint will crack, chip, whatever, if the substrate is improperly prepared, or if it is flexing, itself. The paint isn't the problem, the preperation is. Stress cracks come from the substrate, not the paint.

As far as fuel resistance goes, I have better luck with Rustoleum, but Krylon does a reasonable job.

A good finsh can be produced when using rattle cans. Surface prep is the key, as it is in any paint job.

In these pics, both models were painted in Rustoleum.

The Cessna was painted using an HVLP gun, from paint available in quart cans.

The glow powered Cub, was painted from spray cans.

On both models, the fiberglass parts were primed. No open bay areas were sprayed with primer, as they flex, and the primer would crack. Rustoleum, Krylon, etc, are all flexible enough to spray over open bays without future problems.