i've found the fifo diagnostic images for reference/delta images to be incredibly useful.
it would be fantastic if those were linked from somewhere instead of being something you have to find in the docs and cut-and-paste to a web browser. a link from the live view would make sense -- plenty of available space. if the write diagnostic and fifo options are not engaged, then disable the buttons. i think seeing them there would let people know it's worth turning them on to tune their motion detection settings.