I prefer to have the mains graphics after the output, so that room EQ is not reflected in board recordings.
I also want to hear the mix "normal" in headphones, not an inverse room EQ.
Other than the possible exception of a crappy unbalanced EQ that is not capable of driving a long cable run to a remote crossover, I can't think of any reason I'd ever want the main graphic inserted on mains rather than in series with the output.