I think it’s more of an etiquette problem than a feature problem. Posting the same thing to many different communities should be deleted as spam. The multipost in your screenshot is certainly spam. Report that. If you want to post something and don’t know which community fits best, or feel like multiple could fit, then just post your thing to one community. If other people find your post especially interesting, they can crosspost it. To me, cross-posting your own posts is a sign of an overinflated sense of self-importance.