I did wonder why the Greenfield wiring diagram showed a wire coming out of the ignition switch for the lights, still not sure which wire that would be on it, but I am like you, I would rather not accidentally leave the lights on after switching off while I go and have a cup of tea and come back to a flat battery with no pull start!!
That would be so that the supply to the lights from the battery runs through the two switches in series.
Then if the ignition is off and the key removed, passing 'aimless fiddlers' can't switch the lights on and run the battery flat...
