Knowing and insight, and intuition, are one and the same.
I agree that, in my experience, knowing and intuition are of the same faculty. But there is a great discrepancy between the two in functionality.
Perhaps it would be fairest of me to say that knowing is just intuition, but the improved still mind and awareness one can attain allows it much greater clarity, certainty, ease and depth. In general, it's like an improved prescription to your glasses. Are you seeing better, or do you have better glasses?
But revelatory insight, in my experience, is far more multi-faceted. I experience more than one insight at a time during revelatory insight such as the "kundalini awakenings" I first posted on here in case histories. Those felt like connecting with everything, all knowledge, at once. Knowing, or, intuition, in my experience, is simply one after another. But, again, perhaps it's simply the deep state which allows us to see a greater breadth of knowledge at once.
You've been here a lot longer. I am not going to pretend I know better. But it seems like there are many ways to look at all this, such as how you mentioned you see Eckhart's book as "something new" he found, due to the different terms and practices he uses.