That’s one of the issues that need to be worked through. It’s a totally legitimate concern.
In cases where communities with polarising viewpoints discuss the same topic, it would lead to inter-community disputes and exacerbate some instance relationships.
One solution would be to have the original community be responsible for moderation, and moderation actions from cross-posted communities only affect their “view”, so to speak.
I don’t know what the answer is quite yet.


There is, but I am not sold on giving up entirely on the idea simply because disparate communities might not want to talk to another.
I agree that treading lightly is paramount, but the benefits of cross-community interaction could very much be worth it!
One thing is for sure: making this an opt-out is not the way forward.