Co-operation is not affiliation so there is no 6th tradition break. that would only be if you put out flyers or the like stating that this is where you come to get your court cards signed. At our meetings it is left to the discretion of the secretary to whose cards are signed and whose are not. If they hanging out and not in the meeting. no signature. If they are there but listening to a walkman - then let the artist formerly known as sign their card. If the secretary doesn't want to sign anyones card than they aren't.
Because you are so close to the court, I would suggest to the group conscience that you don't sign and that you close the meeting so as not to have to shut it down. But that's just my not-so-humble-opinion, and what do I know?