That's a shame, I guess that the combination of tolerances between the extruder tip and the fan mount are such that I have more room between the heater block and the tip than you do. I assume that you have pushed the fan duct up as high as it will go before tightening the screws? It can touch the Kapton tape as there is a ceramic insulator between it and the heated element. My extruder tip is approx 2 mm lower than the bottom edge of the duct, yours looks to be about 1mm above. You need some clearance as the duct will knock things off the build platform it it's too low.