No doubt it pays to be cautious given these are new and few have experience with them yet but they do have circuitry that will shut down if overloaded. Some here are already using them in two motor diesels. I would first run the engines before installing a new board to see what they actually draw. Total stall can happen but its pretty rare. Usually the wheels will slip if the engine can’t move but do whatever you are comfortable with.
As for lighting I have one incandescent and two LEDS driven by the headlight circuit. The grain of rice bulb only draws 25ma and even with the LEDs current draw is a fraction of the 100ma output rating.
Pete
