I'm not sure I understand still; when I was a student I found my classes to move at a tediously slow pace, often going into detail about and even repeating obvi

I'm not sure I understand still; when I was a student I found my classes to move at a tediously slow pace, often going into detail about and even repeating obvious things. Even in university engineering classes (e.g. walking through "Fourier's trick" multiple times when it's just a dot product/projection). You seem to be saying we need more of that (and maybe that's true for most people!). Wouldn't that mean tracking is a better solution? Let the advanced kids who can quickly understand/infer the ideas and techniques move on, and walk through the details/give lots of practice to the other kids?