[sondr3]

This also made me scratch my beard, but I think he maybe means allowing multiple mutable references to a variable when the compiler can prove that nothing bad happens. It's something a bunch of people have been trying to solve with different models, the most recent I know of is Tree Borrows [1].

[1]: https://www.ralfj.de/blog/2023/06/02/tree-borrows.html

[Georgelemental]

Tree Borrows is a model of `unsafe` code (for example using raw pointers), it is not a proposal to change what the safe Rust borrow checker accepts.