The TFA sample I have is a complete mystery to me. How it passes for chocolate I've yet to work out. It smells OK in the bottle, but once you throw it on a hot coil, it just tastes artificial

.
I agree with
@bombastinator, that chocolate vapes are a difficult flavor to replicate, and not for everyone.
Chocolate concentrates seem to be one of those flavor groups that is
very temperamental. It is more sensitive to heat (lower is usually better), and can be easily influenced by inferior quality nicotine. For me; chocolate performs better on +1.0 ohm MTL coil builds, compared to sub-ohm DTL builds (airflow has a significant influence too).
If you question your nicotine quality: try vaping two identical mixes in identical hardware. One mix with your usual nicotine profile. And, the other exactly the same (same flavor percentages, same PG/VG ratio), but omit the nicotine. If there is a significant difference... it is the nicotine.
Also, chocolate concentrates can easily be over-used. Chocolates, for me, need to be started at, or below, minimum recommended percentages. When using chocolate in combination (with other chocolates); keep the combined total low.
I would have NEVER thought to use AP to help out chocolate... Mind blown.

Like 95% of my "wisdom," it is not a "Joel original." I learned most of my chocolate understanding from other mixers. I think it was HIC who exposed me to the idea of using AP with chocolate.
Chocolate mixes, for
me, have almost always become closer to a more realistic chocolate, when using more than one chocolate concentrate, in the recipe. It seems like flavor manufacturers always manage to get one part right, while missing others. Combinations of chocolate seem to fill these voids out (HIC's Swiss Bliss is a good simple example of this).
The only exception to this, that I have personally found, is a
Reddit Recipe called Rumpelstiltskin (by InsigmaTheory). It is a German chocolate cake recipe, that uses FLV Chocolate Deutsch, as the only chocolate component. It tastes exactly like I remember Mom's German chocolate cake; rich, chocolatey, with a distinct toasted coconut note (from the FLV Chocolate Deutsch; so not ideal for a plain chocolate). InsigmaTheory's flavor notes for the recipe are worthy of a read.
Finally, a DISCLAIMER:
Before anyone starts thinking I am some sort of a chocolate guru, I want to state
emphatically, that I have never been satisfied with my chocolate efforts. I have attained "adequate," to even approaching "decent." But, I have never arrived at anything that I would classify as "great." I have burned out, for the most part, on chasing chocolate. (Every once in a while I still dabble.

)
My experience tells
me; chocolate vapes take:
reasonable expectations, a LOT of patience, and a willingness to try lots of subtle variations (both with recipe formulation; as well as hardware set-up). Without
all of these, one is set up for heartbreak, and frustration.
