About mounting backward.. for left/right thread is plain stupid, but is achievable if the threads are already mashed.

I installed the spindle backward on purpose to adjust the chainline (i swapped double rings with single ring for fixed gear).

Also on italian/french (same thread on left/right), the cups have different lengths from the face to the raceway of the bearing, so that gives more options to adjust chainline by installing the cups backward, or the spindle backward or both.