The two bucks and doe I had in front of me last night were downwind for probably 20min. Don't get me wrong, they stopped and threw their noses in the air a couple times. However, after a couple checks, they went back to their business and hung out down wind of me.
I think the biggest factor is not getting picked off for movement. If your local deer herd starts to equate the smoke smell to hunters, then you are not going to see much activity and you might as well spray down and continue to play the wind because your scent smoker will become a neon sign over your head.
As for deer smelling you, I think that's the most amazing thing about it. It's almost like daring them to pick you off sometimes. They smell until they can't stand it any more and never smell you. It's incredible.
In regards to the "neon signs", it'll take generations for an entire herd to develop that survival instinct. No doubt you can educate a single deer to the smell, but they'd do the same if they smelt your stinky ass. I have no fears that the vast majority of the deer in my area will equate smoke to me any time in my lifetime...