Joe
In CCP under tools/nesting settings do you have your depth of cut set first pass is where you can leave your onion skin and then second pass will cut clear thru I cut full depth with a 1/4" bit so with a 1/2" bit doesn't seem like it should be that bad except for all the pressure that bit is applying to your plywood trying to move Also have you set material thickness in every cabinet and saved it in a file The picture almost looks like it thought the top of your table was the plywood I only run.20 Z clearance doesn't seem like you should need 1.75 safe Z