Is there a reason why this is implemented in Rust instead of plpgsql? At first glance I didn't see it using any features that would need a loadable extension. Plain SQL based solution would make using it on managed database services much easier.
Distribution of Postgres extensions is a challenging problem that we're working on over in https://github.com/tembo-io/trunk // https://pgt.dev/. One of the goals there is to make it easier to install extensions.