I'm working on a similar project for a similar concept that involves spacing reading material called Incremental Reading[1] so it was a pleasant surprise seeing your project, great work.
For exporting to Anki, I suggest you look at Anki-Connect[2] if you haven't already.
I have been using Anki for the past 6 months (2021-Jul, present), before that I used SuperMemo for 9 months before that (2020-Oct, 2021-Jul), the reasons I switched to Anki are plenty (Linux/MathJax support being the top ones).
My project is not related to the Incremental Reading Anki plugin.
https://ankiweb.net/shared/info/935264945