I used the design mentioned as inspiration for a mount I can put on my shoulder strap. I didn't like the way the center engaged the Garmin. I used the center from another design found here https://grabcad.com/library/soporte-garmin-1 .

It's kind of a tight fit, but I think my printer over-extrudes a little bit. In future versions I might make it slightly longer to make it easier to twist the Garmin in and out.

Thanks!