I don't believe the Halo tobaccos are WTA (whole tobacco alkaloids) nor of them being NETs (naturally extracted tobacco flavors).
If you go to Halo's website, to a tobacco flavor, there are 4 boxes between the flavor description and the ordering section. If you click on the one that says "Premium Flavorings", this pops up...
(bold added for emphasis)
(GRAS - generally regarded as safe)
I'll take this as a no to your questions. If I'm interpreting this wrong, I'm sure Rocking Randle or someone else will chime in.
As an aside, I have vaped Torque56 and Prime15 for the past 16 months. Along with Malibu and Belgian Cocoa, they are always in my permanent rotation, and I can't see myself without them.