There should be a switch to limit the crop edges to the area of a tilted / rotated image.
With rotated images, you currently can extend the crop area beyond the image border and then you get a black triangle shaped area.
Although this might be desirable under certain circumstances, I guess most people don’t want to see the black triangles.
Automatic crop does not cover all needs: I often want to have a smaller crop area than the maximum area, or to move the maximized crop area off the center.
P.S.: This request has already been posted 2017-05 in the old forum http://forum.dxo.com/index.php/topic,13387.msg69021.html