Yes, that’s what I meant. I heat up the nozzle in order to retract… and then I extrude to get rid of anything that might be left… and then I let it all cool down before I put my fingers around there and change out the nozzle.
It’s not needed, but will keep your heaterblock alot cleaner.
My old printers didn’t have one and after a few prints the strings made the heaterblock nasty. And cleaning this block is not ideal .
As for the burning part, mwahh I can say it’s still very hot for the user to touch when your at 200 degree C.
It will keep your temperature a little more steady when printing at high speeds. As cooling and item that is heated can also result in a more steady temperature. But only when the heat is greater than the cold