I live and ride in Mexico and my F650GS is my main transportation and daily rider. We get high humidity and high temps like you do in Australia. Since new, I have always tried to keep the tank at least half full when riding. First reason was the fuel pump cooling issue, second reason was the sound the float makes when you are moving the bike around in the garage, that knocking sound was a real WTF? moment at first, then I realized what it was. Still don't like the sound of it, though.
I have had an experience at very high elevation (4,200 meters) in sand and gravel where the yellow light came on indicating something, seemed like it was an overheat. Fan was on, temp was up a bit, and it stopped flashing when I coasted down to a lower elevation and never happened again.