When did they appear? Was it some time after flash time or right away?
If it's right away that could be contaminants.
I never had solvent pop on Epoxy but if it's a dozen small holes why not block it out and spot in some epoxy? It's not much more work and you wouldn't have to wonder about that area and how it will hold up. If it's a reaction and not solvent pop then sanding it down will just give you the same problem again cause it will re-reveal that stubborn area that gave you problems to begin with.