I think this is the point where area experts would be of help. Platforms could pay panels of people who have expertise in mental health, medicine, etc. to screen any given flagged post and decide if it fosters harm. It doesn't have to be a total free-for-all of censorship. It can be that a post simply gets flagged for expert review, and if the experts condemn it, then the post gets slapped with a warning label (like a pack of cigarettes) for its readers.