Something I don’t get from the article is if the students are to collectively help decide what the class will study or to individually help decide what each will study. If the latter then I don’t see how a teacher could keep up with it all.
At Summerhill, each student decided, for themselves, what they wanted to study and did so. That means that a kid who didn't care about math, didn't study it; the same re any other subject, after only very rudimentary learning ( simple math,how to read ) was done.
In N.Y., a class would decide what all of them would "study", from a choice.One class, in a public grammar school, chose South America for three or four years in a row, which, of course, meant that after the first year, none of them had to do any homework ( they already had all the papers, etc. done ), study for tests,etct.! It became a cause clebre and once found, was stopped. OTOH, there were a number of "experimental private schools, all over this nation, in the early to mid years of the 20th century and they tried out all kinds of outlandishly stupid stuff. Almost all of them failed rather quickly; though not all. There's still one that is attached to Bard College.
This article is a vague, so I can't help you there, because I too am not completely certain how it has been installed.