in FACT, I don't think it can be done, which to the extent that I have a point, is the whole one!

I agree with almost your whole paragraph here, and that is why I am challenging the set-in-stone function order that people keep spouting as if they KNOW these things when there's no real way they can without making "confirmation bias" type assumptions. If I followed the prevailing attitude around here, I would say something like "I'm ISFP, so my tertiary function is Ni, so these things I do here must be Ni, since I must use that for something." I believe that is like deciding where the end zone is on a football field by how far the running back ran - in other words, cart before the horse, backwards.
So, thank you for helping continue to prove my viewpoint that brain function is not as simple as people are making it out to be, and that when people say stuff like "that was my Se-Ni at work", they are making a giant guess that really isn't provable in any way and just comes off as a cute way to label something.
Oh, so you already know that. Well, then, that makes my job a lot easier.
Function notation is nothing more than a complex system of interlacing metaphors.
It isn't real, at least not in terms of action. That's the whole REASON I like it. If people had these functions in a real, measurable sense, I probably wouldn't be that interested in them. If you're looking for something real, you're looking at the wrong part of the system.

This is the edge of it, where it borders into fantasy. This is quite literally an attempt to figure out what dreams are made of.
Function notation itself is very Ni. It's an attempt to describe a perspective, not an action. Perspectives are useless by themselves, I'll grant you that, but when you begin to figure out what actions a person associates with a particular perspective (and accept that people are inherently aware of certain kinds of perspectives that interact in a particular way), they become meaningful within the mind.
This will be my last attempt to describe Ni. It's absolutely
not about reality. If you look to reality for an explanation of Ni, you've already rejected it. It's about the mind that understands language, symbolism, and associations. In other words, it's about what the world symbolizes to people because of the inherent nature of our minds, not the world itself. Everything we know about the world itself... is everything that Ni is NOT. It's actually much easier to express what Ni isn't, than what it is. Because once you express it or understand it, it's not Ni anymore.
This is really all the meat behind the functions. If you go much beyond this, you're speculating. Almost everything that we say or theorize about a function is speculation based on these cores:
Te - Efficiency, goal-driven
Fe - Consideration, service-driven
Ti - Analysis, logic-driven
Fi - Integrity, value-driven
Si - Standards, security-oriented
Ni - Visions, future-oriented
Ne - Ideas, process-oriented
Se - Experiences, present-oriented
You'll notice that these are things everyone is aware of on a basic level. We essentially use them as a metaphor system unconnected to type. They're sort of like Tarot cards, except that you decide which one is most relevant to the situation and best describes the situation via a hunch rather than leaving it up to luck.
Well, then I suggest you re-orient, because you have put yourself in that situation not me. I am simply information gathering, and I'm doing so in an interactive way, that allows me to challenge and question ideas and actually get response, rather than just reading a website somebody wrote and having a ton of questions but no one to ask. I'm not spelling out or outlining my current beliefs because they aren't substantial enough on this topic yet to even have a coherent outline. I think I have made my basic view clear as to why I started this topic. I read several descriptions of what "Ni" is supposed to be, and found almost all of what I read to be negative attributes. So I was looking for people to tell me what the positive ones are. I am slowly starting to learn the possibilities of this. Of course I remain skeptical, and if you are expecting me, a hardcore SP if ever there was one, to at one point just say "Okay, I totally buy into this!" then you are expecting the impossible. The only things I totally buy into are what I can see demonstrated before me and perceive with my own senses.
Okay, then. Well, I have to be honest with you. If you read a lot of descriptions of Ni, and see it as mostly negative attributes, then that's what you think of Ni. There's no point in trying to make you see it as something positive, because the interpretation is subjective. All it means is that whatever you associate with the Ni perspective and archetype is something that's highly uncomfortable, and antagonistic to your preferred worldview, whether you realize it or not.
If it's any consolation, I can't see anything positive in Fi, either, because it seems to be rooted in a lot of uncompromising, stiff, ethical nonsense that doesn't really accomplish anything. Si is almost as bad, but I can see a certain value in it despite seeing it as mostly negative.
That's actually the nature of functions. You're going to look at some of them and go, "Yes, yes, that's it, that's what I find meaningful," and you're going to look at others and think "Oh, my god. That's what all those people who make my life miserable are doing. This way of looking at things is horrible, no wonder they're so screwed up, they value THIS."
You're
supposed to be able to find value in all the functions, but that's like saying that you're supposed to love everyone. In reality, we don't love everyone, we love people who we can relate to on some level, and end up just tolerating and/or disliking the ones we can't relate to at all. That's just human nature.
In other words, I really don't want to sell you the function system as something that can be measured in terms of real actions and consistent behaviors, because it just plain ISN'T that, and anyone who tells you that it is either:
1. Doesn't know what they're talking about.
2. Trying to trick you into believing something false.
3. Deluded because they can't separate the validity of their subjective experiences from observable fact.
However, I would invite you to look at it as something else. A kind of poetry, a kind of language. Words are not reality, but we use them to represent aspects of reality. Functions just regularly try to do this with much larger chunks of reality and the typical human experience than most words you're used to.
Take a word like "infinity," or "universe." It's so expansive that you can't wrap your mind around it, right? Well, functions are kind of like someone trying to understand infinity by trying to look at it from as many known angles as possible, and then making inferences about what the possible angles we're aware of, imply about the nature and limitations of our minds. Yes, it's quite a leap, but it stirs something, makes you really think about what life means. It's the ultimate attempt to look at ourselves from the outside.
All in all, you might be better off sticking to what works. Because honestly, even I wouldn't use functions over dichotomies when typing someone initially. I only use them as a way of helping them decide if they feel conflicted, and they don't feel that dichotomies and temperament are giving them enough. They're not practical, they're just an open-ended theory with no apparent application to reality that we like to play around with and speculate on how it MIGHT be related to reality if it were.