Out of curiosity, did you use an existing package for sm-2 or did you implement it from scratch?

I only ask because I've implemented various sm-2 packsges in Python, Typescript and Rust and have made them available under the MIT if anyone's interested: https://github.com/orgs/open-spaced-repetition/repositories?...

(Also, nerdy aside, but the original sm-2 technically had 6 possible ratings)