Quite the opposite; jemalloc has been the default, and using the system allocator has been the "hassle" since well before 1.0.

However a few key platforms have jemalloc disabled because it's buggy (deadlocks or worse). I think as of a few days ago it's pretty much universally off on windows.

Also whether jemalloc is used depends on how you build your thing -- dylibs use the system allocator (because they're subordinate), static libs (rlibs) inherit from the thing they're linked into, and executables use jemalloc (because they're in control).

Then that's the reason. The config is a dylib, so I have to force it into using jemalloc, which I cannot do when using stable.