This is interesting; I feel inspired to respond.

to inspiration!
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Thank you for so clearly revealing your methods of communicating. It's a wonderful and illuminative post; I appreciate the detail and it is mind-expanding to read and ponder. I am still engaging with it on a number of different levels.
I want to share some more on this topic, and as an INFP to an INFJ. In case it didn't appear clear, I adapt to the people I am interacting with as well, in a similar manner you describe -
except if I diverge too far from a certain locus, or am around a great number of people, the chameleon-like nature of my interactions starts to seem false to me, as though I am losing my core self in there somehow. (That I am merging too far and will lose the essence of me, to all these people who need / enjoy different aspects of me.) The core is what I want to stress here though. The way I choose to interact in the world
IS an expression of who I am. I don't view it as layers, I see it more as a set of concentric circles, where the closer you get to know me the closer to the core you get. But the core is always ... there. Does that illustrate any difference between how I see myself and how you view yourself?
And to add some extra nuance to this, if I am "reading" you and also adjusting my interaction to connect with you, but you are ... staying neutral, remaining uncommitted to a path of interaction, I will likely not pursue a relationship with you. It won't be overnight, and I will try again to connect, but if I sense you reading more than you are giving I will simply emotionally block you and not permit any exploration of my psyche, nor will I feel willing to lay down a pattern you can piece together over time. I will block you before you block me (generally speaking). Which saddens me, because I don't meet many INF's in the "real world" ... but, I just can't chameleon around someone trying to get a bead on me at the same time and taking notes.
As you rightly concluded, cascadeco, I am not judging the authenticity of Fe / intent at all, but - and here's the big but - the price of really connecting with you will feel too ... insecure to me. If our time communicating is like water, then I need to know where the shore is located. Also, the sense I generally receive - that you are storing a library of our past "moments" to use in the present - can feel disingenuous to the reality of NOW. I don't know how else to explain that at the moment, so forgive that. I will expand on this and try to clarify later.
I know only a few ENFJ's / INFJ's IRL. The ENFJ is a charismatic helper, out there in the world doing what he sees at the greater good, and he is a fabulous man in many ways. The issue with him is when he confuses his own agenda and vision with what is best for the group. In other words, his agenda takes over without his full awareness that he is failing to see all of the group's POV, or even caring about the division he is inadvertently fostering.
One INFJ is my age (40+) - she feels secretive one moment, warm the next. I continually feel watched and it makes me uncomfortable. So my reaction to her (because I sense her depth) is to open a little wider so she can see more of me and in return I hope to see more of her. But she again connects one moment and pulls away the next and stays private, and never really shares with me what I am hoping to be able to share back. And she is uncomfortable to know that I "see" things that almost no one would ever pick up on (I had to tell her not to worry, that she is far from an open book to 99.9% of the world.)

But I know that it just makes her wary in general so we don't talk about this type of stuff at present. She's very intelligent and accomplished and I really admire her, but I can't continue to put myself out there and receive only monitored and measured interactions in return forever.
The other INFJ I know is 20 years my senior. He is quite open and candid and has a wealth of experience that gives him a shape to me. I feel his scanning of me and I permit it, because he does not stay in that space. He goes back to his own core, and shares from that, and we have a lovely Fe dance with each other that is both humorous and enjoyable. I tease him a little in a dry, sarcastic way ... I would say we have a medium-level interaction, where I let him know about certain parts of me and he in return does the same. It's a comfortable relationship.
I guess what I am saying is that ... if you are trying to watch me all the time, I will just block you out. Then you will likely drop trying to read me (thus place me in whatever category you wish on the Fe rate-o-meter) without me having to do the dirty work of avoiding you.