I think related to your caveat is:
https://lexi-lambda.github.io/blog/2020/11/01/names-are-not-...
> The newtype is opaque, so the only way to observe it is to convert it back to a [f32].
https://lexi-lambda.github.io/blog/2020/11/01/names-are-not-...
> The newtype is opaque, so the only way to observe it is to convert it back to a [f32].
If NASA were to use the equivalent of `pub struct Newtons(f32); pub struct PoundsForce(f32);`, where the types Newton and PoundsForce were not interchangeable, this would never have happened[1].
[1] I'm aware that that story is a bit more complicated than that, that CSV files were involved (which are, again, not type safe), and that, in that particular scenario, more would have to be done to preserve type safety across formats, vendors and codebases, but my point still stands.