Don't know if there would be any interest in this type of mount. I redesigned the Garmin Edge mount I was using so that it is only an eighth-turn instead of quarter-turn. As a result I ended up being able to put two sets of stops 90° offset. This allows an Edge as well as a Forerunner or Fenix to use the exact same mount without moving and/or unscrewing anything. Then I put it in a Time Trial Bar Extension type of mount. The Garmin will sit even with the extension. As an added feature I put a Virb mount under it. You can have both a Garmin cyclo-computer or sportwatch as well as a Garmin Virb action cam all on the same mount. The Virb will sit below the extensions. It should fit any alloy/carbon extensions that are in the range of 20-22 mm in diameter.
Only a couple of items are required. An M4 x 15 mm socket head cap screw, an M4 nylon insert lock nut, a genuine Garmin Virb mount insert and locking ring.
Here is a render of the mount.
This same mount could be made with a built in GoPro mount also.