Using 2-pot varnish years ago (before epoxy finishes became sensible and normal) I applied between 12 and 15 coats! The first one was about mostly thinners, with just a little varnis: that soaked into the wood very quickly and dried in about 30 minutes. The next had a bit more varnish, and so soaked in a little less, the third coat was almost the recommended mix. These are all applied on one day. At that stage, the gain in the wood has risen, so you can rub down again with 800-1000 or so wet and dry and get the surface very smooth. Then 5 or 6 more coats, another rub down, and then the final 5 or 6 coats. The final coat is again VERY thinned (as long as it doesn’t run!!), as this gives the quickest drying, fewest flies, best looking surface.
But these days, I would go with 2 coats of epoxy and 2 to 3 coats of normal one-pot polyurethane varnish.