I was never a chain smoker unless drinking, but I was like a clock. Needing one every hour just before the hour at about a pack a day. (I don't sleep much) Anyway, I felt like a chain vaper, because I always seemed to be abusing my equipment (stock 901 auto). I read a neat pdf document from this site under caring for a 510 or something of that nature. The interesting thing I never considered was to have two or maybe more in your case at hand. It said something like:
Only take 3-5 long drags at one time and then let it rest for 3 mins.
So it did seem that to satisfy my timely craving I would hit it fine a number of times, then struggle to produce the vapor or nicotene I needed. This would lead to frustration and battery changing and over juicing and dripping etc. What I really needed was another e-cig with me to puff on right after 4 or so good puffs from the first. I would be good at that point or go back to the first one.
Maybe they could make a mod to keep the e cig hands free all together, like I would do while typing at my computer until the smoke got into my eyes.
hope that helps