Which specific FA concentrates are you testing? (12% does sound high to
me, for FA concentrates, but I have only experimented with 27 of them.) What percentage(s) are you mixing them at (did you start at 12%; or something else)?
I can't speak for anyone but myself; but I find smell (aroma) a poor indicator of actual mixed potency or taste. however; I will be the first to admit that my sense of smell is pretty poor
. Sense of smell
does often play a big part of how, and what, we taste (I can taste almost
nothing when I am congested; vape, food, or beverage). But I can't seem to get an accurate sense of what something tastes like until I get it in my mouth.
What type(s) of atomizer(s)(brand/model) do you prefer to vape with? What coils, and resistance of, do you use in them? Specific setups can have substantial differences in flavor requirements.
Old-school CE4 clearomizers, Stardusts, and Vivi Novas, which are classically higher resistance, and stingy juice-sippers, can require more flavoring; than low-resistance, juice guzzling, cloud-chucking, drippers and tanks that are more prevalent today.
Also, power (wattage) and airflow settings, affect taste. If you are using a variable wattage, or voltage device; be sure to experiment with higher, and lower, power settings. Likewise, if your atty has adjustable airflow; experiment with tighter (more restrictive), and looser (more airy), air flows. You might be surprised at how much of a difference these small adjustments can make (and they can vary from flavor to flavor too). The answer is not always "more concentrate."
"Too much" concentrate can actually have unwanted results. It can overwhelm your taste receptors and cause the flavor to mute and disappear. It can add unwanted "artificial", and "chemical" tasting elements, to your mix.
I find, for
me, when working with a new flavor; it is best to start low, and increase as needed.
Now that I have said all that; only you can decide how much flavoring is right for
you! People who have recently quit smoking, or still smoke, often require much more flavoring, than someone who has not smoked in quite a while. Individual diet can have an influence as well. Strong flavors (especially those which are oil-based; like coffee, garlic, and onion) can overwork and coat our taste buds. Which, in turn, can make one need additional flavoring.