A "sane limit" wouldn't be "one person one IP", such a global limit should rather stop one IP (even if it's a nasty CGNAT) from having a negative impact on the

A "sane limit" wouldn't be "one person one IP", such a global limit should rather stop one IP (even if it's a nasty CGNAT) from having a negative impact on the entire service. If such a limit would hinder classroom usage, but that's your target audience then other solutions should be found, fairly logical.