On my BBSB refurb, I only used epoxy on the outside of the hull. 2 layers of 6oz cloth, top and bottom, and about 5 coats of epoxy (way overkill). Outside looks like a fiberglass hull, no evidence of the planks still seen. I would not make it so heavy if I was to do it again. On the inside I painted everything with oil based paint. White rustoleum anywhere the birds can't see to reflect light well, and FME everywhere else. I store the boat in a tent. If I come home with ice in the boat, I will park it in the garage and turn on the heat to melt the ice. I sponge out the water, and place a box fan across the oars over the cockpit, blowing in. I will run that for a couple days during the week until she is all dried out. My thought on paint and not epoxy inside, is I knew I would never get everything sealed, and then if water got in, maybe it could not get out.
I might do it different with new construction, and certainly would with a plywood stitch and glue build.
Whatcha building?