Double part cooling fans

I want to try out this ( design for double part cooling fans on thingiverse. Is there anything I should be wary of when connecting the two fans?

I am thinking that I would just connect the two fans in parallell configuration to the original part cooling fan slot on the extruder board. Do I need to replace the resistor on the extruder board to make sure that both fans still receives 12V?
I also wonder if there would be any signifcant risk for heat creep or other potential problems with the hotend, due to the fan ducts in this design?

This will probably be OK but depends if the fans can cope with a PWMed signal.