Just for the record, I've had a lot of success with polyester gelcoat over epoxy repairs. I think this perception comes from open mold production where you don't want to mix the (wet) two types of plastics.

If there are any substantial chemically reactive properties left from the epoxy resin post cure, something didn't mix or cure properly. Once cured, it's just a solid plastic just like a polyester based product and you are getting nothing but a mechanical bond with anything you put on top of either one (paint, gelcoat, etc.).

Ok, back to your regularly scheduled program...