I love this! One thing that comes to mind in our school is that while students tend to meet the descriptive terms in the 'Flow' category, that isn't a state they can stay in on an extended inquiry. That is to say, they are following their passion, in charge of their own learning, have intrinsic motivation and want to share what they are doing with you... but I wouldn't call their state 'flow' all the time.
Some days it can feel like a grind. Some days they are digging into things they don't really want to, but it is necessary to further their learning. For example, as a byproduct of wanting to print a 3D Model of their Tiny Home design, 2 boys 'learned CADS'. That wasn't part of the project, wasn't easy, wasn't something they necessarily did in a 'flow state' and yet some pretty amazing learning was happening. It is more of an 'autonomous learning' state than a flow state in my opinion.
That said, I'll end where I started... I love this! It brings to light the dynamic way in which I think education is shifting from content and classroom management to student engagement... and of course, personalization! :)