and when it hits you have to reduce all your trims screwing up your
monitor mixes(assuming monitor from house in a live rig)

Changing the trims the same amount will scale down the monitor mixes. I
guess one could quickly compensate by upping the gain on the aux send
masters.

Musicians do not appreciate the volume swinging up and down on thier
monitors
this would not be a issue with a seperate monitor desk
but your board tape still gets f*cked
George