In that case, none.

It could work if the student is challenged and tested by the LLM itself and his performance overseen by a human evaluator. But I wouldn't know.

A learning scenario is very different from a work scenario or daily assistant scenario.

I think there are many ways in which LLMs can harm humans. Almost all of them are "use on others for psychological influence" ones. But hey, even that could be seen as training if you have the guts to handle the pressure.