bubber, this button doesnt vent because button's axis closes this hole. I dont think that the man made this button thought that the button could vent this way. It was just an accident and he couldnt repair it.
GGTS has already 12 invisible venting holes. There is no other mod out there with 12 venting holes and vertical ones so GG will not come to customer's mouth if battery exploded. We dont need more venting holes for sure
If it was an authentic button, the only I can think is that the customer polished the button too hard in a wheel and the hole get exposed. But you said that this button is thinner than GGTS's button so its not mine for sure