They he first steps in prepping the power supply boards after the case has been removed. A more open design means more airflow as well as adding more active cooling. The specs say the board is rated for 500 watts ,but the specs on the board indicate 600 watts. Usually to get the most out of a power supply you need a good cooling solution. Three things allow this, a heat sink, open airflow and forced air movement on the heat sink and board. Given this is mounted under a drones 12 props air movement is in abundance. We really do not need a fan dedicated to each heat sink. I may reorient the heat sinks so that the canes are vertical, but I am guessing this will make little difference given how turbulent the air will be moving.