My current thought is that the subtype system that makes most sense to me is one where there are the following 2 subtypes:
- top function/IE/whatever subtype, where there is a relatively strong preference of the base/leading function/IE over what socionics would call the "ignoring" (eg Ne>Ni in NeTi types, Ti>Te in TiNe types, etc), and a relatively greater balance between what socionics calls the creative and demonstrative (in a NeTi type, this is Te, Ti); not uncommon for it to have emphasis on what socionics calls hidden agenda (called tertiary in JCF)
- secondary subtype: similar paradigms to the former, but reversed. That is, e.g., in a FiNe type, they are "in a sense" more emphatic on the Ne>Ni but not directly, so much as through greater emphasis on rejecting the POLR through staunch following of balanced Fi/Ne.
I don't mean that these are the only combinations. I think that there are some aspects of the types more related to temperament than cognition, and I reserve dcnh labels for describing those.
I just think the above combos are good for describing the most cognitively or conceptually relevant varieties.
I admit some influence from Jung in selecting, and I believe Jung referred to the first subtype in his types where he proposed that e.g. a Ti-dom has the hardest time with Te (even more than with Fe, somehow).
I currently am identified with the first subtype of ILE; of course, I am actively thinking about this, so I'm less sure than I am with the overall ILE result.
Now I mentioned a third subtype (I think the "first" one from my above post), which is the "irrational" subtype of ILE, IEI, etc; personally I've come to believe that extreme irrational and extreme rational are less likely subtypes to occur in practice, due to the fundamental need for pairing irrational and rational. This isn't to say they don't occur. Jung describes an introverted intuitive woman, who is probably best seen as this subtype. But I don't think these are the most common ones in practice. Those are the extreme one-sided ones.