This is not a balance, not in a scientific community.
There is an immense gap between the scientific discussion of these kinds of issues and ideas, and the kinds of bad-faith polemic argumentation that takes place in spaces like exploding-heads.
We should not welcome those spreading mis/dis/malinformation as part of our community. We should not welcome their forms of argumentation as legitimate. We should not welcome their "questions" and "claims" as part of the debate, all in the same ways that these ideas and forms of argumentation are not welcome in the scientific literature.
You started this instance not as a "free speech bastion" but as "An instance dedicated to nature and science." A dedication to nature and science requires the forms of moderation you resist. A dedication to nature and science does not mean unmoderated, unregulated discussion.
What you do now drives the culture and the norms of this community. Every second you wait further entrenches this kind of speech as acceptable by the leadership of this community.
I'll hold my "engineers really need to stop making social spaces by themselves" rant for another day.