The entire premise seems to be that if you are stuck using not Rust in some way then CHERI helps. How is my comment not correct then? This is a bandaid to help poorly written code handle memory faults with hardware exceptions. MMU and MPUs do this as well without the cost of fat pointers which is non negligible. Rust does this with the compiler before the firmware even runs.

Is it neat? Sure. Is it practical and useful? I’m skeptical.