cheater holes: not always good for "woosh"
My Multiplex Twister was a bit too quiet with a low-power CS70. Cut some cheater openings in the EDF hatch, and it makes more noise now, but not much woosh gained, rather you get to hear the motor whine more through the openings.
But it's still a change for the better, and I think the performance is slightly better because the fan is getting more air. Mind you, that is only a <400W setup...