great thread friends
I just read through, a few thoughts come to mind, hope you don't mind
1) the nic is part of the equation. whatever AVE uses, its an in your face, high pepper, high alkaline-note, high TH kind of nic that I would guess is MFS/Wizard Labs. Nic has a flavor, taste, feel, etc, and its not a neutral bystander. The more sensitive your palate is, the more true this becomes.
2) there's def a difference between VG, VG/PG, and PG juices, so keep in mind they will effect flavors differently. if you're getting really close to something, and you can tolerate it, I would switch (for purposes of the project) to 100% VG. PG indeed has a taste, as does VG, and they're far from neutral in the way they affect a mix.
3) using the color of juices to track down flavorings is indeed valid, but keep in mind that flavorings/nic in VG vs. flavorings/nic in PG will color, discolor, etc, differently. Almost all of my VG blends (well, they're all VG blends no adays) with *anything* sweet in the mix discolor to a rich brown/amber
anyway I'm lamenting the fact that I don't have a good graham cracker now

but I do have acetyl pyrazine, it used to be one of my 'die without' flavors.