I've been analog free for nearly six weeks now and I still find myself chain-vaping, even liquids I know are 0mg, and even when the 18 I use isn't giving me a buzz any longer. I do however notice I only do it when I'm bored now, as opposed to my first few days vaping 6mg at a party when I was getting used to the new delivery mechanism and trying to sate the desire for a good buzz. Moved to 18mg, wake and vape, and I'm set until dinner most days, but after that I'll retire to my room, hop online, and find myself unconsciously chaining for hours just to have something in my fingers or mouth.
Take-away: Everyone's different, I was never a 2PAD smoker or anything so I can't give you a baseline there, but logically all the above posts make sense saying you'll chain-vape your first few days off analogs as you try and get that same hit you're used to. Give it a few weeks, see what happens, then I'd look into either a higher nic level, or maybe as someone above posted, a liquid with WTA in it.