We've been on both sides of the fence: At a CG wanting some rest and at a CG wanting to visit with friends/family later than quiet hours. When we've been on the wanting rest side, I try to understand that the neighbors have just as much right to mingle with friends as we have to be quiet. Now if someone is out of control and really obnoxious, that's a different issue but if they are just enjoying each other and their voices get a little above normal from time to time, who am I to stop them from enjoying themselves? I can turn up the TV, Turn on a fan/ac or put in some ear plugs. I'm not sweating that small stuff. If they are having a bean bag tourney as mentioned above and everyone is cheering loudly after hours, maybe that needs to be respectfully addressed. If they are hammered and being belligerent, treat it accordingly.
Maybe the answer is to have space in the CG that is geared more toward quiet hours and another area where it isn't that strict. Kind of the Knot on a Log loop and the Live it up Loop. The CG could also price accordingly. If the Knot loop is full, they can put Knots in the Loud loop at a discounted rate. Maybe charge a premium for one or the other based on demand.