I tried to explain to him how idiotic that sounds and he always replies with "Well, that's how the big boys do it". I know that he needs help. Just wanted to share this with the forum so I can show him how idiotic he sounds.
Ask him which main eq? Even on a relatively simple system I'll have a stereo parametric on the main fader, but I feed the PA off the matrix outs (always) and I'll have another stereo perametric there. I'll also have a graphic eq inserted on the main fader just for quick and dirty adjustments after the show starts.
Sometimes I will adjust that graphic eq to suit my vocal mics IF I have several mics that all have some problem frequency popping up. Easier to just cut that once and call it a day.
So which main EQ? On a big-boy rig there will be dozens of EQ's for all different parts of the rig.
Home Schoolin is showing his ignorance here.