Wow....I had no idea this would spur so much intuitive thought lol no offense. It's been stuck in my head for days now pouring over medical journals, figured if I put it to writing, it may be easier to understand. Understanding the basics of addiction, I find the anomaly strange to simple not want to smoke, or vape. Still vape? Yup. I enjoy it.
Perhaps someone who DIY mixes and has someone else in the house that vapes with nic would be willing to do a study? Replace a bottle of the other persons ejuice without their knowledge, with a non nicotine blend, and report the results???
The latter part of your post would be cruel to a fellow human being (w/out their knowledge) & if someone done that to me, just to perform a self study, I would have a severe issue with this.
That's because there's some people, who may have smoked in the beginning to self treat anxiety (this was the deal with me) & I would know fast if a switch was made. Though oftentimes I vape for the flavor, there's other times when it's for the physical need.
No one would be well served by monkeying around with my e-juices & I'll let it go at that.
Cat