Calling Kotlin from Rust (and other languages) is useful when you want access to an existing Kotlin codebase and would rather avoid creating a full-blown port. I guess most people don't do things like this because creating bindings for languages that are not C (or C-like) is usually cumbersome. Krossover is trying to fill that gap for Kotlin. Does that make sense?

pretty much!

I'm still curious about case studies. I can imagine that something has SDK for Kotlin but not for Rust, yet outside of that case, technical benefits are not yet obvious to me.