A flow bench does all of it's work on the chamber side. When flowing exhaust you reverse the flow and open the exhaust valve, so there would be no way to have it push on the exhaust and suck on the intake at the same time
However, if you did want to optimize, you could chase low lift flow on the intake side, I am no porter, but that doesn't always help higher lift. Best is to have a port that is clean and not too much volume
