I don't think I'd vape in a line, or queue, whichever you prefer, unless it was outside and a sideways breeze was blowing. That's too much like dumping on the cologne/perfume, then standing in an elevator or other enclosed space with others who may not share your taste in fragrance. (And where are the laws and regulations about that?)
I look at it like smoking a cigarette, and there are places and situations where I wouldn't smoke, and in many of those I won't vape either. Laws and regulations be damned, there are situations or places where lighting up is not polite, regardless of the "legality" of it.
At a table in a restaurant or tavern with friends/family, after asking management, by all means, I say and do vape away. One of my pool teammates still shakes his head every time I blow out a big cloud of caramel-chocolate vapor and comment on how well it complements a nice dark beer.