upon further experimentation i figured it out! I should have realized this earlier. the x-knob (MDO) controls how far over zero the flange goes. So the closer to 50 the closer it gets to going over. At 50 it goes over. The farther past 50 the more it goes over, which means it has to come back past zero, thereby cancelling a second time! So at 50 it's absolutely perfect. I also highly recommend when using mono to use the 2nd output instead of the first to get that way crazy over the top flange. 

Off hand, does anybody know if using the second output has any effect on any of the other presets? I went through all mine and didn't seem to notice a difference except for thru-0 flanging.