I wanted to show off this gist I wrote: https://gist.github.com/Superstar64/30c5793ba4315f4794d20a837d80ef9b

It showcases how to create System F-like polymorphic using type erasure. It was somewhat inspired by this paper: https://www.microsoft.com/en-us/research/wp-content/uploads/2016/11/levity-pldi17.pdf