The Sapphire Pro has a problem with belt-misalignment, so I searched for a solution and found this one made by StoneFPV/StoneTime. I had to remixe it a little, because it didn't really fit my pulleys and the tolerances of the holes were too high.
Remixed from: https://www.thingiverse.com/thing:4772013
BOM: https://docs.google.com/spreadsheets/d/1CpRTM5ExVKjqFqKXyHM_BEqhV6jeapgpBublu8SchCU/edit?usp=sharing
The author marked this model as their own original creation.