Ahhhhh. Homebrewers. We look into absolutely everything despite it being isolated.
The leak is clearly isolated to the gas in post o-ring. He replaced all of his keg gas in o-rings.
I guess what is in question is there bigger ball lock gas on o-rings than normal? I think not. I think they are all the same.
Once again it’s not a lid o-ring issue, a lid sitting issue, etc.