What you're talking about is blush. Will the epoxy blush and cause resistance to further adhesion. Generally slow hardeners don't blush like fast hardeners. Blush is a waxy chemical that sometimes gets released from the epoxy when hardening.

I looked up your epoxy and I see they make a UV proof epoxy - interesting. I would call them and tell them what you are doing and get their advice. As the others said, they are all a bit different. I use Raka no-blush and never had to worry about that. Ask your epoxy people while you're at it if it blushes or how much. There's usually a time window when epoxy will chemically bond with a previous coating with no problems.

I never pre-coat either but that's another long debate.