Granted, my understanding of looking externally for identification is likely going to be different from ISFP per my Ne-Si as compared to Se-Ni, because for me, it tends to be finding identity in externally communicated concepts or ideas

What do you consider to be a concept, an idea and a theory? MBTI is a huge reference point for me but I can't confidently state that it is a theory due to a lack of fulfillment of scientific criteria, I would say it's more of a concept that provides a system of categorizing information regarding our psychological processes, but scientifically speaking I'm not sure if I would consider it a "theory" yet because it doesn't provide enough consistent evidence to back it up, so I think concepts can also be used by ISFPs if it serves their own goals.

I think the line between what constitutes a theory or a concept/idea can sometimes be blurry, especially in fields like psychology, so what I'm asking you is how do you differentiate between an idea, a concept and a theory and what kind of ideas are you usually looking for when looking for identification? And does this mean that you are constantly re-evaluating yourself depending on which ideas you decide to explore? It seems we have the same goal but different ways to go about it.

For me, as an ISFP I will find one singular archetype that I am trying to embody, an ideal future self, and then everything I research/do will try to fulfill that specific end goal. To give you a random example of how this works in my head, it's kinda like starting an RPG game with different classes, choosing one of them and thank thinking about which stats/skills should I develop for that class.