I have made a parametric mount for GoPro, using it also for other purposes.
you can change the tolerance of:

• plastic
• gaps
• holes
  in Fusion 360 you find those 3 parameters.

It was hard but I found the real sizes of Go Pro Mount:

"General" GoPro slot mount
Plastic thickness : 3.02 mm
Gap : 3.12 mm
Hole : 5.09 mm
Outer radius : 14.88 mm
slot depth : 15.66 mm
hexagon: 9.5mm face2face

Important:
some compatible mounts have tighter gaps (at the bottom), so you have just to increase the tolerance of 0.1.
If you print SLA you can use tolerance =0.0 as the material shrinks a bit under UV, but it is always a trial&error process, once you find what best fits for your printers, just take note of it.
what you find it is perfect for me and for my CR-10.

Creality

CR-10

No

No

200

25%

I suggest outer wall flow: 95%