What's wrong with iterating on Rust? Comprehensive type checking makes refactorings a lot easier than something like Go. And you can iterate starting from a simple, working solution that relies on marginally more expensive features, such as .clone(), Rc<…>, Cell<…> or RefCell<…>, Any for dynamic data etc. etc.
Refactoring is safer with Rust, but in generaly Go is not so unsafe that refactoring costs more than it saves on the frontend. You can write a lot of Go (and contrary to the memes in this thread, you can still leverage the type system to great effect wrt safety) in the time it takes to get a little Rust to compile; however, Rust is getting better all the time.