but I also feed bad for people only on the .world who might miss content
That doesn't happen because everything is federated, the .world users will also see the posts on .ml, they can upvote/downvote, comment etc. and vice-versa.
Yeah I tried out the dev's other project RoundedBSE but for some reason that made all the text blurry. Looks like spiky corners it is until KDE introduces this feature itself. I am surprised they don't have this baked in since how customizable it is.