I'm using LLMs alongside Math Academy. Math Academy uses machine learning generally (and so now they plug their "AI" technology) but it's not transformer-model-style AI ML; as I understand it, it's just driving their underlying spaced repetition system (which is interleaved through lots of different units).

In the scenario I'm discussing, Math Academy's content is a non-generative source of truth, against which I've benchmarked GPT5 and O4-mini.