Thank you, Actually it's not as common as you'd think.. I spent a lot of times observing mating couples and never saw it happening.. And when they're still young not and not full grown adults, the risk is minimized especially if they are at the same size. of course I did some testing before putting them together, to see if they are interested in each other (meal wise)..
Well you certainly went through a trial and error state that obviously is very detailed as you explained it and honestly its just wow, really something but yeah<< normally im not even one to look at pics like this but guess somehting about it made it a sort of exception but your saying its possible for the fem not to devour the males head off right away?
Sure, "Although the praying mantis is known for its cannibalistic mating process in actuality it only occurs 5-31% of the time. Especially in laboratory conditions of bright lights and confinement, the female is more likely to eat the male as means of survival." Source - [link]