The DCNH system is considered official valid socionics. I didn't write it, I just quoted it from a socionics book.
I had 0 idea I was LSI for example. Most ppl aren't self aware enough or knowledgeable enough to determine their own types, let alone someone else's. One would need to be a trained socionist and even then mistakes can be made. The other problem is validity of duality. Theoretically it makes sense, but in practice I have seen stuff like SLE women not enjoying the idea of a IEI man, because "he is weak" and other things that make sense outside of socionics in terms of evolutionary biology.
:shrug: I could not get along with self typed EIE either despite commonalities. To think one is different or special and can manage all of this flawlessly.. is to be deluded. there can be many other factors that interfere EVEN if one gets the types right.
Imo its just not something one can reliably predict relationships with. You are better off using
relationship styles or just going with your own best judgment.