@BeAware I don't know if instances can moderate this if every instance, perhaps even every user, is shown a different text.
If the original post is not public, it is very difficult to compare how other instances see the same post in the Fediverse.
If you want to harm a user, you could show them a picture of a cute cat to get them to comment, while everyone else is shown a racist picture. It will be extremely difficult for the user to explain why they wrote a positive comment.