The compiler aspect is no problem; I’d expect the present tool chain to handle it with minimal effort. However, Rust needs its own runtime, and this is likely to be a piece of work on a machine with secure stacks; you can’t just muck directly with the stack links on a Mill.
I agree that it would be an interesting and useful project. We’ve had several requests for Rust beyond your own, but no one yet has stepped forward and offered to join the team and port Rust. Offers, anyone?