First, be advised that this model might damage your Wahoo unit if the print is not precise enough. I still added a tolerance 0f 0.20mm around Wahoo's own mount files, but the printed mount might scratch your unit. For testing purposes, you can always download a file of your particular model on Wahoo's github here : https://github.com/WahooFitness/ELEMNT-Mount. Also, you should test the mount with a nano Voilé strap on the stem on their own because the strap's tension could break the mount depending on what filament you use. We wouldn't want any expensive piece of technology to break in the making of this project.
Orientation: Same as the file
Supports: Yes (this print only works with supports)
Filament: Any not too stiff filament that goes outdoors, like ASA or PETG (I used PETG for mine)
Layer Height: The tiniest the layer, the less friction on your GPS unit. You could always lightly sand your model if you want to use bigger layer heights.
Here's the link to the Straps i used : https://www.voile.com/nano-series-straps.html
The author hasn't provided the model origin yet.