So much useless EXIF info, and no lens ID ...
I strongly disagree with the notion that superwide lenses cannot stand scrutiny. They indeed can and should. If not only to convince oneself that the concept of hyperfocal setting never was applicable. The sharper the lens, the less convincing hyperfocal focusing will be.
As to the new series of test images, do have a look at the pavement front left and right corners. The problem is very obvious. One could of course blame field curvature but that would require *both* corners to go out of focus concurrently, which they clearly do not do. Thus is is not field curvature that causes the very uneven distribution of sharpness, whether it is the Milky Way image (at infinity focus) or the architectural snapshots shown later.
When I evaluate a lens, I only rely on what I can observe myself. Plus, the observation(s) have to be repeatable.