I have hardly found any 1xbit campaign participant which are high quality posters so far which indicates that the percentage of spam created by all these participant is much higher compared to other signature campaign participant. So now, any 1xbit spammer should be banned from using signature if the quality of their posts is just total trash and bullshit.
It makes sense that decent users stay away from this campaign, so that only leaves shitposters who have nothing to lose, but I don't think they will get banned just because of the signature they wear. I also don't expect them to get a signature ban.
To get them a real ban, I think you'll have to build a case against each individual user. Back when Yobit was spamming, suchmoon made an overview of the number of posts per user. Such an overview could help here too, but it's a lot of work and I've seen users get away with
many deleted posts.