The first Stern Jurassic Park I saw in the wild had the stopper in front of the top right flipper sheared clean off.
That worried me as I was buying a JP of my own. I know a guy who maintained pins and said they would add stuff to the bottom to help support it on their games.
Since I bought my own I've been worried constant shots to the post will eventually rip it off. So I made a protector/support to help support it on the top.
I't very much like plastic protectors, laser cut from durable PETG plastic. It goes OVER the triagle shapped plastic near the flipper and extends to the button screw.
Hopefully this will provide some support from the top to help stop the post from slamming forward and loosening the screw/drill at the bottom.