I think your idea is a very good one! I am in the process of finishing a stitch and glue kayak. Several times in the last two weeks I have resolved (for my next kayak)to put a thin coat of epoxy on each of the panels before beginning assembly. My reasons are different from yours. I found that during the assemby of my current project, the panels got dirty, got drops of untidy epoxy from the gluing process, and generally just didn't look as nice as I wanted. I think that putting a light coat of epoxy on all panels prior to assembly would prevent a lot of the cosmetic problems my current boat has.