I looked for Firefly Q6 mount on Thingiverse, but couldn't find the type I like. One that looks good is not in Stl format, and not watertight too, others have no ventilation for air circulation, while others I didn't like.
Ultimately, I decided to design one... and the result is here :-). Camera fits very nicely with a little snap/click. It has ample of vents for air to circulate that keeps camera cool, is light in weight, easy to print, and securely holds the camera.
It can also be attached to any GoPro compatible mounting system.
I am also including my Cura gcode file ready to print (for Tronxy P802MA).
Remove all supports, and file the edges if necessary.