Great job on these boards !!
By coincidence , I've been working on a couple of Red and Flame Birch boards in the shop today. Just came up for a break while deciding where to put the fingerhole in one of the boards , and here are your great examples : )
I usually use Mineral Oil as well , but I just bought a quart of GF Salad Bowl Finish to try on some boards.
Already don't like the fumes from the stuff and the long wait time until they can be used. I'll be going back to the Mineral OIL and Beeswax on my next boards.