Swapping out allocators won't cause some programs to crash and others to not crash unless your program is already using up all available RAM or your program has

Swapping out allocators won't cause some programs to crash and others to not crash unless your program is already using up all available RAM or your program has a bug and the allocation pattern happens to be more likely to trigger invalid memory access in a way that crashes. This allocation pattern idea is unlikely to show up in any real application except at the absolute limit where your exhausting RAM and the OOM killer gets involved. Even then I think you're going to not see the allocator be much of a differentiating factor.