All of what you're suggesting has been proposed in the past, but at this point I'd rather just keep them quarantined in the off topic section than them infecting any where else as you'll just get them shitposting wherever is easiest for them and they'll move from board to board until there's none left. The problem again comes down to shoddy signature campaign managers who don't really care where someone is posting or about the quality of those posts. If people are abusing the off topic section or anywhere else and there's specific campaigns that are paying them for this then they should be dealt with. People can make decent posts in there but the whole reason it's become a cesspool is because of the few campaigns that are allowing themselves to be abused so they should be dealt with if they're causing a problem.