I'm coming from a fairly specific experience.
But the answer has turned out to be never. Generally because it involves convincing other people of it's patterns for it be adopted as a useful metric for discussing issues with others (I'm coming from outside of forums or groups like this one). For a distanced observation in which a person might...say....fill in the blanks of behaviour with a best set explanation in a quick not-too-analytical and interpersonal-in-the-moment sense, it tends to be as good as most on that account, the account of best guesses.
On the other side of it I've definitely never had any single person give me a useful, meaningful or helpful (and any other adjective of that nature) interaction or set of information using typology (which is not to say I haven't got that from the people I've met on here) that comes across as harsher than I intend but it is accurate.
Particularly if it's from a personal assumption of what they think my type is, what they think their own is and how they believe that fits together.
It's just another kind of assumption surrounding behaviour and so far it's always been wrong, though I give a sliver of allowance that it could one day be right.
Mainly, the pattern I notice now, when you hollow it out, is people end up exchanging different content for the same feeling of certainty and being "right". I'm no less guilty in this respect and at the risk of accusations of projection: it's partly how I recognise it, however I can recall when I first clicked with typology and the elation of that epiphany, the feeling of 'rightness' that it brought was kind of addictive. Although I was never a prolific out and out typer, in fact I was always more interested in it as something that could tell me about myself (yes that is as stupid as it sounds). Later in another post-identity phase or rather the illusion trying to cover for another illusion, I thought about how easy it was to believe in something.
We seem to be somewhat hard-wired for it, to an extent, I mean we do it whenever we get up in the morning. And interestingly empiricism seems to be inherent too, we can credit our senses with that one.
Basically I knew I was dumb, but never sure how dumb. So I started to enjoy the breeze on my face; I stopped being mindful and started being worldful.
We live in a world of things and are made up of things, there's this perverse arrogance where we seem to assume sublimation of the things to our will, when really we're more like the subjects ourselves.
The greeks had it right with their concept of the muse.