I wrote a paper that in large part was a response to P0581, so yes, I've read it a few times.

https://wg21.link/P1453

It sounded like you were trying to make a point. Can you be clearer about what that point was?

On Mon, Mar 9, 2020, 02:25 Ville Voutilainen <ville.voutilainen@gmail.com> wrote:
On Mon, 9 Mar 2020 at 11:16, Bryce Adelstein Lelbach aka wash via Ext
<ext@lists.isocpp.org> wrote:
>
> > From a users perspective, having STL modules would speed up compilation times immensely
>
> As I said in my email, standard library headers are already importable in C++20. So your implementation can already replace #include <vector> with import <vector>;
>
> I don't know that we can really do that much more than that; we could have an import std.vector, but it sounds like (0) std::vector would have to remain in the global module and (1) standard library implementation details would probably have to remain in the global module as well.
>
> TL;DR the use case you described is already covered in C++20.

I wonder whether the people commenting on this thread have read
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0581r1.pdf.