I have some experience helping previous jobs block bandwidth abuse from user uploaded content. That lead to inadvertently finding some pretty bad content. I would figure out some way to have someone else review the content or at least some kind of automated scanner you can use to pre-check the reported content before reviewing it yourself.

Some stuff is hard to unsee.

Edit: I wonder if a local LLM (to help with privacy concerns) would be a good option or not to at least identify anything obviously bad. Wish I had more concrete suggestions.