My thought was that flavorings were USP grade food flavorings (one desperately hopes or who the hell knows if they’re safe or not) and as such we’re designed to be cooked. Is this not the case?
That is a fair point. Flavor manufacturers like TFA, FW, and CAP still get the lion's share of their flavor concentrate profits from sales to food and beverage sales. And, "food" applications could well include heat (baking, candy making, etc.).
If I am being honest, I have to say; I don't know what, if any, correlation there may be between cooking, and e-liquid applications.
However, I also do know there are some differences in handling. They have other flavor and aroma sources, from other ingredients, aside from flavor concentrates. Cooking also has the luxury of possible use of oil-based concentrates, which may(?) be more heat stable. Also, food & beverage applications often use the flavor concentrates at much higher percentages than e-liquid applications.
Just from my own brief experiments with heat and its usefulness to DIY; I found that some concentrates (like custards, cheesecakes, and tobaccos) were fairly unchanged by moderate applications of heat (140-160℉)(though some tobaccos lost desired aromatic qualities). While other concentrates (like citrus
(esp. lemon), berries (esp. strawberry), and most florals) suffered dramatically. As always... YMMV.
speed-steeping with quality results is a myth imo.
That has been my personal experience as well.
