I would try reducing PG level as well. I've had clients who complained about the same issue, I ended up reducing both nic and pg levels to fix it. As for the craving for nicotine lowering over time, it's true. Something a lot don't realize is that tobacco contains 4 other addictive chemicals that are directly related to nicotine, and addictive like nicotine. Nornicotine, Myosmine, Cotinine and Anabasine. Nornicotine when in processed or cured tobacco becomes a carcinogen, and still addictive. So when you finish withdrawing from these, all that's left is the Nicotine, and it isn't nearly as addictive as you might think by itself.