I guess I should post some of my findings...
I've used TFA Kettle Corn, and even at .5% it overwhelms the mix and drifts away from the caRnY4 taste. I often dilute caRnY4 with a mix of 12% TFA RY4 Double and 1% acetyl pyrazine down to around 1/10th normal concentration to make it last longer. The flavor doesn't change, only the intensity which tells me those are the main ingredients (or FA RY4 which is very similar IMO). Adding Maple and Vanillas to blends also made them drift away instead of closer.
The closest I have gotten is by adding TFA Caramel Original to a mix of:
10% TFA RY4 Double
1% Acetyl Pyrazine
1% Trimethyl Pyrazine
1% Tetramethyl Pyrazine
Everything tasted right except the caramel after a couple weeks steep. Adding TFA Graham Cracker Clear in equal amounts to the Caramel Original seemed to get closer but still not right. I believe the mix of pyrazines is what causes the popcorn like flavor and wife hating exhale smell. Peanut Butter flavorings use these and are a more likely ingredient to me but I haven't gone into fine tuning that portion of cloning.
So far I've used Capella Caramel, LorAnn Caramel, Hangsen Caramel, TFAs Caramel Original, Caramel Candy, and tiny amounts of Caramel Cappuccino. All were too light and candy tasting instead of caRnYs dark rich chewy caramel flavor. I plan on trying FW Salted Caramel and HIC's Samoa Recipe to see if any of those hit that flavor note I've been missing.