Vedders Anti-Spark Switch damaged by plugging in?

Hi, is it true that it could damage the FETs if the Vedder Anti-Spark switch is plugged in while the switch cable is not connected to the Anti-Spark pcb or if the cable is connected but switch is in ON position? If so could you explain to me why that is. I’m asking because I’ve fried one of the FETs recently. Best

Per @goldenHusky

Just solder the external SPDT switch onto the switch pads and turn the switch off before you connect the big wires to your system. And I recommend switching off only when your board is standing still and no motor is spinning. Otherwise this could cause an inductive spike killing the Mosfets.

Hi thank you for the info, hope this time the switch will last a little longer.