I'm a gameplay programmer who have worked with Unity and Unreal and I've experiment with Rust for gamedev(though only for hobby projects) and for regular code. My conclusions so far is that Rust sucks for gameplay code, for most other things it's kinda nice.
The biggest reason is that it's much harder to write prototype code to test out an idea to see if it's feasible and feels/looks good enough. I don't want to be forced to fully plan out my code and deal with borrowing issues before I even have an idea of if this is a good path or not.
I would say though that because you are using ECS stuff it is at least plausible to do in Rust but at least for my coding/development style it still isn't a good fit.
Not really. Unsafe doesn't allow you to sidestep the borrow checker in a decent way. And even if you do it the Rust compiler assumes non aliasing and breaking that will give you loads of unexpected problems that you wouldn't get in a language that assumes aliasing...
Testing something that only has side effects to the local scope is probably not too hard but that isn't the most common case for gameplay code in my experience...
Going through another language basically has the same issues as unsafe except it's worse in most ways as you'd need to keep up to date bindings all the time plus just the general hassle of doing it for something that could have been a 10 min prototype with most other setups...
Now sure it's possible that I would have better result after doing even more rust, especially with some feedback from someone who really knows it but that doesn't really change anything in just general advice to people who is already working on something in C++ as they likely won't have that kind of support either.