I remember being on an 18 hour flight sitting next to a guy who chain smoked ghastly turkish tobacco and blew it in my face LOL Probably the only time I refused a smoke.... Oh the good old days 
If I were to stealth vape on a plane, it would have to be using a cheapo that I didn't mind losing to detection and confiscation. I still don't see why a hit here and there is considered unallowable on a plane. It must have been the jealous cigarette smokers who wanted it gone.
I remember the good old days when smoking on a plane was common place. It was inconsiderate of us, but they even had lighted signs to let you know when you could.