There is no setting whatsoever to specify that you're wearing the watch face down. In no way does that change which side the crown is on and in no way would the screen have to flip or rotate, anyway.
I always found it odd that people prefer to wear their watch like that, and this just seems like you're asking for the screen to crack. Unless you're constantly sitting in zen position, your watch will not be visible if you want to just glance at it.
Also, if you wear the watch facing down, chances are it's not going to be able to pick up your heart rate, pulse, etc. Go ahead and try taking your pulse on both sides of your wrist and see what happens. One side you clearly can do it, while the other side is impossible.