I agree that crossposts (be it the same community or not) should be visible from All / Local / Subscribed feeds.
It is currently not the case (only one post is showed, I never understood which one was selected) the other post is completely invisible, this hides conversation which might happen in two places at the same time
Ideally there would be an indication about the crossposts in the feeds themselves (rather than at the post level like currently) to avoid this