it is a remix of the fang for Dual stock.
I didn't try myself so please leave comment/remaks !!
print @ 0.1mm layer
If printed at 0.1, no support is needed if you have at least 3 perimeters, with proper cooling and slow speed when you reach the high angle overhang area, it will be nice enough to do the job.
print @ 0.2mm layer
At 0.2 you will need support, but be sure that NO SUPPORT are inside the duct, parameter should look like "from build platform only". it will be ok.
Personnaly, I have printed the dual with a 0.2mm layer up to 46mm and then 0,1mm to finish the print (i used 2 process with Simplify3D, i don't know if possible with other slicers)