And speaking of primer, here is one coat of Interlux Pre-Kote at left, after a first round of sanding. I started looking closer at the surface, and reading a bit more, and I realized that primer is not primarily to help the paint stick to the epoxy. Noooo, it is primarily to fill in the imperfections in the lumpy epoxy finish on the plywood. So, after some more sanding, we get something more like at right. You can see, that I sanded a good bit of the primer off (and I even did a bit more after this pix was taken), but the resulting surface is MUCH smoother than before the primer. So, if you are trying to decide whether primer is a good idea or not, this is something to consider.
And here is the current state of painting. I have finished 3 coats off-white Interlux Brightsides on the inside of the transom and the seat longitudinals, and the inside of the cabin (the latter was not fun to paint!), and have two coats on the cabin sides and front. That will be the last of the white, and then I will move on to beige.
My shop has a temp hovering around high 60's but mostly low to mid 70's lately with our heat wave, and I have found that 5% thinner works pretty well, but paint starts getting sticky after about 30 minutes. So, if I anticipate a section taking longer that that, I mix the full batch with thinner then pour 1/2 in another container which is covered until it is needed (had to do this with the inside of the cabin, which took about an hour to paint, not including the hatch details).