It's got to do with our headspace as you have so eloquently described it... we have everything going on in there at once... so to jump from topic to topic... is to stay on topic. Nothing is out of bounds because everything is connected. You're not leaving an idea behind, you're just looking at it through a different lens, from a different place. I think most of my mind operates out of the bounds of time. I don't really have time awareness unless I'm explicitly working on a project and am probably engaging a good amount of Te. Otherwise everything runs together.
i follow what you're saying. the shift in place is really valuable to me, and why connecting with Ne doms is so untangling. in general, it's a bit easier for me to see the process with my entp 7w6 friends because of the judgment transparency, but most of the time, when Ne doms preface, "this is maybe a change of subject, but i swear it's kind of connected," within the first two sentences i usually see and smile and am happy with the way they are refiguring and revoicing the melody (with that right-brained prosody). so i don't actually find Ne doms to jump around too much at all. on the contrary, it feels like home to me. for Ni doms, to be in a space, to be engaged with someone who is a master of space, helps us feel part of the flow, the currents that meet and move forward, outward from the moment.
similarly, i think, that sense of FLOW is really the biggest thing that marks self-mastery for Ne doms, a way of being with time, movement, and change of perspective in a continuous stream of possibility. finding a balance, especially for head types, of the explosion of enthusiasm and mental sprinting, which is really endearing and also intoxicating, and being able to stay with the process enough, stay close enough to the ground and go slowly enough (distancewise) to really be present, is the kind of game that takes practice. the prize is an ability to accept and stay with experience and create space for appreciation and enjoyment that optimizes, in a non-invasive way, the processes going on everywhere around and through it, in a way that balances freedom (possibilities!) and responsibility (actuality/consequences/inheritance of the past, a way of honoring that and trying to do your best, your part, regardless).
as for keeping time, i've been thinking about this a lot, because i have so much work to do in this area. socionics claims T has to do with materiality, whereas N has to do with time. i think creating definition/definiteness and measurable distances is necessary for keeping time straight (literally linear). it's like when you're a kid and you sketch in one continuous line or you shade in with short strokes. F might be better at feeling the dilation of time--the confluence, center, and gravity of it--rather than controlling it and taking control of the moment in order to be as efficiently constructive as possible. T brings a kind of balanced creativity, defined by specific, concrete landmarks, actually measuring the force and distance and tipping point rather than operating as much from personal mood/whimsy, a kind of imprecise holistic impressionistic time. rather than one that is exclusively being caught by the endless songs of sirens, attracted to everything, jumping from solar system to solar system without a coherent self, without anchors. T then helps offer parameters to author a self within our own defined spaces, our own boundaries we have constructed to a materially constraining degree, that helps us more precisely know and measure where we are at within our own game/story, our own project/goal structure.
If you really need an explanation, Nardi is probably as close as you're going to get with that, and his studies that are starting to explain dominant Ne as a result of an inclination to use "christmas-tree" transcontextualism to think about nearly everything.
