I decided to design my own backpack mount. This one allows the camera to face forward, which I think is better than facing the other way because then you have to use selfie mode and that tends to lock onto faces that pass by and screw up the direction it is pointing. It also hides the display from passers-by so it's less obvious you have a valuable camera on your shoulder. It can use the smartphone connector to lock the camera into the mount, but to prevent losing the smartphone connector I made a little 3D printable clip with a loop of string for easy removal.
Watch this video to see how it works: https://youtu.be/sQPkJI8Eu-8
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