[LoganDark]

> the default for Rust releases is also to omit many run-time checks.

...because the type system and borrow checker satisfies them at compile-time?

The only checks that are omitted at runtime are:

- checks that are exhaustively proven to be unnecessary by LLVM - checks that can never be triggered in the absence of UB

You shouldn't be triggering UB checks at runtime. If you rely on these checks, you're relying on UB itself, when all UB should be provably impossible.