Every tire I've ever installed, or, in the case of cars, had installed, the dot on the tire went next to the valve stem. I've never heard of it being otherwise, Ernie. Where did you get that info?
Once again, Uncle Ernie's dislexia has kicked in.
The mark denotes the light spot on the tire. Few tires use the mark anymore as production methods have increase accuracy to the point there is, in theory at least, well balanced tires. People lined the mark up against the valve stem, theorizing that was the heavy spot on the wheel (not always the case though).
Michelin never used the spot, as a matter of pride, claiming their tires were well made and round.
Heck, we are happy if the Ural rim has some semblence of round, and not too egg shaped.