david weaver
I can't comment on it drying, but if you are curious about it, cut the blank as you'll cut it to use it for planes (if in fact you are going to cut it). Otherwise, just use it as is. I wouldn't be surprised if it was pretty close to totally dry in a year. Now it's been 2 years, and it's less than 4 inches thick in two directions with all four sides and ends exposed.

I would be more worried about where it will go in three weeks after you've split it down the middle. I've gotten quartersawn kiln dried boards before that still twist when they get in my shop, presumably because the tree was growing with a twist in it (as Bickford's blog shows when he splits one of his logs, the grain gradually spirals up the tree).

But I don't think you have much to worry about, you're almost two years on with the wood, and it's probably about as dry as it'll get without going into a kiln.