Since you're asking about LLMs, there are plenty of Anki extensions that make use of the tech for card creation and supplementation but leave the core database and scheduling loop untouched. Anki Brain (https://ankiweb.net/shared/info/1915225457) comes to mind. My own extension for studying Chinese, Pindu (https://readpindu.com/), uses the output from Anki's SRS as the input to the LLM, and then the learner sees the output from the LLM.
yes it is?
just checked, fsrs is ai