That's exactly how I set it up and it worked for me. Although, it only seemed to blink at the time of the alert...it didn't continue if I left it unchecked. It's also extremely bright (same as the flash, clearly); I'd have expected it to be softened to about half-brightness, but alas.
As far as being face down, mine blinked while being held in my hand and in use...so I don't think orientation matters.