Yes, it is indeed a good trade-off. That strategy is called a region-based memory management in general, and in fact Rust's borrow checker is its generalization

Yes, it is indeed a good trade-off. That strategy is called a region-based memory management in general, and in fact Rust's borrow checker is its generalization, automatically generating fine-grained small regions that are called "lifetimes" ;-) So they are valid approaches, just that Rust borrow checking is much broader that safe Rust covers wide use cases.