I can't think of any reason either.  If the wood is completely sealed and the epoxy surfaces will not be exposed to sunlight you ought to be fine.

I like to add white pigment to the epoxy used to coat the inside of compartments. With two coats, you can easily wipe any spills clean. Adds a nice bright finishing touch to compartments.   

Justin, that's you, correct? I remember reading about that pigment trick on your JustRight website. Your lead furnace, BTW, was very useful and ended up being passed along to GeorgeK, who also hangs out on this forum, when I was done with it.

Laszlo

   The final top coat with white dye will reflect more light witnin the compartment and make it easier to see any object inside.