I would love to see a production ready kernel written in Rust adopted by the industry. I am exclusively using Go and Rust at home and at work, and I find myself equally productive in both. Go lacks a lot of 'high level' features for a GC language, so I don't find the GC to be that advantageous. Rust is safe, fast, and a joy to write. I'm not surprised by these numbers, I would be interested to see a breakdown of compile times for similarly sized kernels in Rust, Go, and C.

Production ready means different things to diff people, and I don't know how many people use it in Prod, but have you looked at redox:

https://github.com/redox-os/redox