For what its worth, I will go out and just say that it seems e-vapes are used anywhere and everywhere in airports providing you are not being disrespectful to people. They are discrete enough that it appears as though you are being mindful, you will have no problems. But then again, they don't sit and puff huge pillows of smoke in the middle of the terminal either.

I see people in lounges and etc charging their pens all the time. I have yet to see anyone get in trouble. But, I've never seen anyone go "Crazy puffing" on a pen - like I sometimes do in public. They seem to be more travel friendly pens, vs. the monster pens some people carry around.