Long story short, I've lost a GoPro 9 because of a thumbscrew and stonewalled by warranty.
I purchased GoPro Hero 9 and the official GoPro mount accessories, large tube mount and grabbag. I've mounted the GoPro on the front shock of my bike for less than a week.
Before every ride, I will check and make sure the thumbscrew is tightly engaged. But during the last ride, the thumbscrew got loose on rocky terrain. The upper part of the mount and the whole GoPro9 camera are long gone after I realized it is not there.
About the cheap GoPro thumbscrew, It is specifically designed to use by hand.
Because I use the mount on a shaking mountain bike I applied a very strong tightening force, basically as much as I can, with my hand till the point my hand cannot tighten it anymore and the square mount base start to flinch by the force. And my hand is stronger than most people I know. But I would not imagine the tightening force if the square base flinches. It is more like a design flaw that the rubber side, which has less material, flinches easier.
Before every ride, I check and make sure the only thumbscrew is tightened this way. Other screws have Philips socket so I can use my torque wrench to apply a 2N.m force on it.
But since this is a thumbscrew I doubt nobody can apply a 2N.m force on it. It is probably 1.5N.m at most with the human hand.
My points are:
1. The screw is a thumbscrew, not a Philips screw. It can be only tightened by hand.
2. The screw is hand-tightened than most people can do.
3. If you have used a Loctite 243 threadlocker, you will know the medium strength of losing/break force is 20N.m, not 1N.m.
4. Consistent vibration is the cause to loose the thumbscrew gradually. I don't think GoPro team can verify that in full simulation. An impact screwdriver uses the exactly same principle to fasten a screw. But in this case, the thumbscrew is forced on the opposite side. I doubt hand-tightening is enough for it if you mount it on a bike on rocky terrain.
And the support case is going nowhere because the warranty doesn't cover the lost camera. It is a shame. I will definitely recommend against GoPro products every chance I got. GoPro is the crown jewelry of garbage. They cannot even fully test a thumbscrew.