I've generally been able to deal with embarassing parallelism by just chopping up the input and running multiple processes with GNU Parallel. I haven't needed the multiprocessing module or free threading so far. I believe CPython still relies on various bytecodes to run atomically, which you get automatically with the GIL present. So I wonder if hard-to-reproduce concurrency bugs will keep surfacing in the free-threaded CPython for quite some time.

I feel like all of this is tragic and Python should have gone to a BEAM-like model some years ago, like as part of the 2 to 3 transition. Instead we get async wreckage and now free threading with its attendant hazards. Plus who knows how many C modules won't be expecting this.