If you pull your finger on the surface of your epoxy surface and see a trail, that's blush. When you wash it with detergent and water and dry it, you won't see that.

The UV scare is over-played/ Supposedly, epoxy can fog when unprotected from the sun. My Greenland paddle has epoxy on it with nothing else and has never fogged. (RAKA epoxy) The epoxy will start to break down or disappear. I notice that the epoxy on the paddle just goes away. I know that sounds bazaar but that's what happens. I wouldn't worry about UV exposure for a week or so or maybe more. I always tested out new boats for weeks with only epoxy on them and never had any problems. If anything, it's water that may cause fogging if the epoxy is not fully cured. I'm not suggesting to take undo risks on new boats surface finish, but to go for a paddle is fine.