Yes, it couldn't not block, it's obvious... but I've encountered non-trivial amounts of "magical thinking" around both async/await ("go-fast juice") and mmap ("go-fast juice") separately, so the intersection surely has a bunch of magical thinking too, where people haven't taken the time to properly think through what's going on.

Hence, my investigation to try to make the "obvious" conclusion obvious to more people.

(Author here)