Cecilia's Horizontal_Scale.sh3d test and other sky textures showing angles that she designed show a zero angle at South rather at North. Cecilia, even if it's not so important, is there any reason for that?

Yes.
It's not a compass!(That's why I named it a scale.)
The degrees reflects the body angle of the camera.
Enter zero for [font=courier new]body angle[/font] , and the scale will point to zero.
Enter any other angle, and the scale will follow.

But note that from version 6.0, you can spread a 360° texture along two walls attached to each other with an arc extent of 180°, by setting an X offset of 50% on the texture of one of the two walls (see example attached to this post).

Cool!
Will there also be a vertical offset for wall textures?

meaning that the width of the texture applied on a curved wall is correct only for walls with a thickness equal to 0 (something that can't happen)

But 0.1 is not far from zero

Cec