GrapheneOS recently gained the ability to selectively disable hardened_malloc for apps, and this is a big usability win. However, I think that usability could be further improved by adding some kind of automatic detection of crashes caused by the hardened memory allocator; the OS would then prompt the user to try using the default Andorid allocator.
As I suspect that detecting memory corruption without special runtime instrumentation (valgrind, asan...) is not trivial, an alternative approach would consist in adding information about the allocator in Android's standard crash popup.
This could be especially helpful for non technical users that might not think nor know about hardened_malloc when experiencing crashes in e.g. games.
Does this make sense to you? Are there any alternatives that you think could be better than this? Any feedback is welcome :D