I keep my blanks standing on the butt end in a closet in a spare bedroom. Buddy keeps his, same orientation, in the attic of his shop - I always worried about it getting too hot and checking, but he's never had a problem with that. Both of us are storing already dried stocks.
I can say how Ron Griffey stored all his wood when he was a major supplier. All his stock blanks were stored in his shop, standing on the butt end. Planks were stickered and stacked to dry for several years, under a roof on the back of his shop, open on 3 sides. I remember hearing he had to have those sprayed a few times a year for bugs.
I always liked how he sealed his blank ends, watched that process once. Melted a bunch of candles in an electric skillet and dipped both ends of the blank 2-3" deep. Could really seal a LOT of blanks fast that way!