I'm beginning to think that they don't exist anymore and that they're an over analysis of something that is too complex that will result in a gross miscalculation based on ideas that are created with misused evidence. In reality instead of subtypes existing, I have another idea. That people of all types go through "modes" where they happen to be using a specific function more than the other. For instance take an ILI that is going through mode will appear to be more structured and pragmatic at that "moment". An ILI going through mode will appear to be more laid back and strange.
This is basically the type using the function that they feel at that moment is most suitable. That being in the wrong function mode would be inappropriate or make things difficult. Subtypes can clearly be interpreted then as someone having a preference to use a certain type of function mode more often than the other one. However, the problem I have with them is they give you a false impression that subtypes are a deeper way of separating individuals of the same time, when they are not.
It is a highly superfluous way to separate people of the same type because the mode that an individual is more likely to engage in does not actually indicate what kind of person they are beyond their standard personality type. My main point isn't that subtypes don't exist. They may exist if you interpret them to exist in that form, you can interpret subtypes to be merely "modes" that a type is going through at a specific moment. This is simply because in the end, most people switch between both of their subtypes depending on who they are dealing with, what kind of situation they're in or the type of mood they are in. Also people may act like a specific subtype for one day and then act like the other subtype for another day.