I’m currently working my way “back in time”, as it were, for my country and a few nearby. I’ve done everything I can for the little islands, and for the two big ones, I’m currently in May 2019. I can guess whether a user is active or not by the number of posts - mostly, they’re not. If I can’t put in any kind of identification, and there’s nothing within Frequently Used Responses that would be relevant, I just mark as reviewed and move on. If a user isn’t active, they may never see me asking “which of these organisms do you want”, or “please delete this duplicate”, but the next unknown-hunter who comes along will see that the user has had that comment, and nothing has happened in the intervening time, so can just scroll on.