I just read our last set of documents, from Summit. (May 13 sailing.)
It seems to be that cigar and pipe smoking is allowed "on the ship's outer decks". To my way of thinking, balconies would be part of that.
Sort of like no-smoking Singapore where you can only smoke when you can see the sky?
I can say that I gave a private party for some friends on Summit in Michael's Club and there was no "stench" whatsover. I took a sensitive non-smoking friend there for the "smell test."
It also tests my imagination that someone would sit on a next-door balcony and smoke cigars all night.
And you can always close your door.