Converter gets hot so I say it gets water flow OK as the heater gets hot also, it needs to go through the converter before the heater tap, with the spark gap there so many opinions on it, some say reducing it to 1mm and others say no need as they work better with a wider gap, main thing is getting the correct heat range. I see how the power side handles at 1.4mm they say keep it to specs as that is at its optimum performance, going smaller will increase fuel consumption they say. Going to big needs more voltage and can misfire at speed. Now I wish I never adjusted them.
Smaller plug gaps will reduce efficiency, saw this on our supercharged engine when we reduced the plug gaps for higher boost and lost some economy at the same time. Been battling that conundrum since.