I had a Moen faucet wrench that worked really well that came with those faucets. I used that design as a starting point to create a wrench specific to Kohler nut sizes.
Print details -
Printed with an outside brim because of how tall it is
2 perimeters with 20% Gyroid infill
PLA - I had a little deformation where the nut interfaced with the print after tightening. This is a one time use tool, so PLA worked great.
0.4mm layer height, but any layer height will work
Recommend printing with a 0.8mm nozzle to reduce print time.
How to use -
Slide faucet bracket over braided sink water line, stick brass nut in wrench, slide the braided sink water line through the center of the wrench, tighten nut and remove wrench.
The author marked this model as their own original creation.