The question was how to mount a tracker with no or just minor interference to both compasses. I checked several positions and their influence on compass reading. Above the battery seem to be a valuable position. It should be easy to mount or unmount because of packing reasons. The idea was to use a kind of back pack adapter, snap it onto the battery and fix a tracker using velcro. You can switch the mavic on/off when mounted, but the battery LEDs keeps invisible. When I decided to upload it to thingiverse, I saw pcardon had already created a similar design. Maybe we are on the same wavelength