MP40s are pretty powerful pumps so you may not need it even at 60% depending on the setting/cycle you choose. Flow is good so as long as not disturbing coral or the sand bed you can keep lots of flow inside the tank. Which mode you choose to keep it on will have an effect as well.
I run 2 mp 40s on my xl 425 one on 50% and the other one all the way down for corals that don't like to be blown around. I put mine on the back wall facing forward. Some of the time the 50% one will blow some sand back but it's not to bad