After buying the Blue Ridge Handlebar Harness from Rogue Panda, I had to think of a way to mount my K-EDGE Wahoo Max Combo Mount so that I could still use my front light and keep my wahoo bike computer in view. 

This is my solution. It has already survived a weekend of bikepacking with my hardtail and seems to be holding up like a bomb. The round cylinder has a slot that is a little less deep than the width of the aluminum frame of the harness. This allows you to clamp the cylinder with half the sphere to the aluminum frame of the harness without it slipping back and forth. It should be a tight fit. So that I could mount my front light, I also printed a suitable Gopro extension. There are plenty of models available.
 

You also need the following hardware for assembly:
1x M5 x 30mm Raised Countersunk Screw
1x M5 locking nut (or a regular nut with some loctite threadlocker)
 

I used regular PLA with 65% infill density (cubic) for increased compressive strength. Layer hight: 0.15 (4mm nozzle)