I'm presuming that even in the modern car world the fog light doesn't go through the ecu or half a dozen computers...
K
Logic would say why make the function of a rear fog light switch complicated, just take power from the headlights and make the switch a momentary function with a relay latch, so when you use the car next time the fog light is off until you push the button again. Simple. However Morgan have taken the more complex route and put that function on the printed circuit board, thus creating a nice little earner when the pcb fails.