I have worked in embedded code bases like that. While some of it is unavoidable for io, I have worked in other codebases where the compile time allocated memory

I have worked in embedded code bases like that. While some of it is unavoidable for io, I have worked in other codebases where the compile time allocated memory was moved around in a way that would have satisfied the borrow checker except for that first mutable borrow. I haven't done rust for uc yet, so I won't claim it is a good fit, but it didn't seem like the parent poster had either, and I think there is a decent chance it could work well of the tooling is there. Which I'm not sure it is.