We have written bugs that this feature can detect, so it may be useful to enable it for our sanitizer builds. The stack_use_after_scope detector is enabled by default and detects very similar bugs, but there are certain cases where the return-detector is required when references to stack memory are saved but become invalidated due to the function defining the stack memory returning rather than simply exiting scope. See https://github.com/google/sanitizers/wiki/AddressSanitizerUseAfterReturn for more details.