WTA is amazing stuff, and I would definitely recommend it if the vaping isn't quite enough to stop cravings. I don't use it more than once or twice a day, and that's plenty enough for me to stop all cravings, along with the vaping of course.
From reading I've done on ECF, I see that people use it in different ways. I have a spare e-cigarette set aside with just WTA in it (6mg, unflavored). Anytime I feel a little jittery, or find myself thinking about a cigarette, I take a few hits of it, and then vape my regular stuff for a few minutes. All better. And the effects last for hours, and often the rest of the day. And a little bit goes a long way.
The way I see it, is that I'm going to use every tool at my disposal to make the quit smoking process as pain-free as possible. The more pain-free it is, the higher my success rate.
Let me know if you need more information. More than happy to help!