450fps, point blank, full auto! Not a very realistic test, and even after the first bursts they didn't fail, but deformed. Any goggle that takes hits like that should be replaced immediately regardless - the lenses have done their job and protected your eye, but will now be a lot weaker. It's the same principle as cycle helmets etc... If you come off hard and it saves your head, you should replace it because the impact will have weakened it.
I see lots of people wearing those exact mesh goggles, but I prefer to stick to higher quality ones. I mainly wear ESS NVGs because I find mesh a bit dark to look through, but when I get too hot/sweaty I will happily swap to my Bitter End mesh goggles to prevent the fogging.
I would imagine that most sites would ban mesh goggles if they were as dangerous as is often made out. Yet every site I have ever played at that does hire kit only uses mesh goggles for the rentals, so they must be fine from the insurers point of view.