An argument perhaps that there should not be hundreds in a room.

Possibly you are describing how it used to be before the input encoding standard for LaTeX switched to UTF-8?

Let me pick on B, on spaced learning and interleaving. In those two paragraphs there are no concrete examples. If a student asks, "OK, I'm at the library and I have my book open. What do I do?" then the answer is not there.

I'll talk about college math because that's what I teach.

If you want students to learn what to do, you have to tell them. Maybe, "Set your timer to a half hour, pick out five problems, three from the current section and two from sections you did last week, and do them. If you get stuck take a peek at the answer, but don't peek until you are stuck. If you get really stuck, mark the question in your notebook and ask about it at the start of the next class. But under no circumstances just read the book." Then you have told them how to practice recall and to interleave in a way that they can actually do it.

Four half hours remembering how to do both current problems and also some from before for every hour spent in class is a good whack at learning the class's material, at least in the first two years.

Just using the two words recall and interleave is not enough.