I never used to drink when I was going anyway as I was with my daughter, well very rarely, but if I did it was before and after I never used to bother in the ground the pints are like piss anyway.
I think enough people turn up after a few and I don't really see how an extra pint or 2 would make a difference to the ones that drink quite a few before and after, they're pissed up either way, the ones that may have the odd drink in the ground and turn up sober won't be an issue, but you're right it would he a nuisance if people were walking back and forth during the game, bad enough getting up to let the serial pissers past.