Really interesting. To provide a personal data point/take, my journey started at a mix of C and D through personal introspection, reading HPMOR by happenstance one day which led me to lesswrong, which then got me started in A at the same time as I was taking a behavioral economics course.
That let me re-approach C and D with a framework more in line with what the rationality community uses since everything was ad hoc before, and I’m just currently at the point of trying to implement the automaticity in B.
Yeah, one thing I made sure to not do in this essay was number the stages with numbers, which I thought might imply more of a hierarchical structure than what I think is accurate. It definitely feels like people bounce around a lot, and I definitely think people will re-approach different places with more insight, which allows you to better grok the models used in that stage.