What positions would a molt be possible from? I know hanging upside down is one, but what about while clinging to a vertical surface like a wall with a cork bark slab?
Most of my mantises appear to prefer vertical space over ceiling, especially the larger they get. I actually think something between a straight shot vertical or horizontal is probably ideal. It would be interesting to see a study done on the success rate based on the angle of the molting surface.
I personally see a majority of upside down molts, but some vertical molts also... Vertical molts seem to get wonky legs more often than others though... where they don't pull their back legs out of the molt entirely so those end up curved and longer. Subsequent molts tend to either fix or exacerbate the issue but rarely remain a mere eyesore.