The front of the frame standoffs are narrower than the next spot back of standoffs which makes printing a little more difficult. Also the typical way of mounting the GoPro using the next standoffs is too far in my opinion.
This design will require you to salvage 2 of the press nuts from the middle plate since you only really need 4 not 8 (they are super easy to remove), and a pair of 3/8" washers or something close. You will be utilizing the holes that where cut in the frame for weight.
I much prefer my crossfire antenna to be mounted high upon the back edge of the GoPro and is secured with a pair of 2.5mm zip-ties. This makes it so there is never a prop strike and optimal signal clearance. Be sure to test if your GoPro Wi-Fi interferes with range and turn off if there is an issue. Coincidental bonus, the Crossfire Antenna will squeeze through the larger opening in the top plate so you don't have to disconnect the antenna ever
Supports are built into the design and pull out relatively easy
*forgot an aspect on my first print, so pictures will be posted soon as I print an updated version.
The author hasn't provided the model origin yet.