I have the K1C. I've turned off the other fans but will give the nozzle fan a try. I've been running PETG at 260C on a flow of 1.0 and it's mainly stringing on gaps or overhangs. I had "slow for overhangs" on the first basket and it had a lot of strings but I turned it off on the second and it was way worse so likely right the speed is a big factor. I've really only had this problem with the White PETG, the other colors haven't had this much of a problem using the same settings.