Reducing clutter by filtering duplicate entries

When entries are pinned or in the side pane, they come up twice in the search. For example, Software Center even shows up three times: Side pane, Uncategorized and System.
See https://wiki.ubuntu.com/inquata?action=AttachFile&do=view&target=Cardapio+-+duplicate+entries.png

If possible, every entry except the first one should be filtered from the results to reduce clutter because of duplication. This should happen in a dynamic, non-destructive way that does not affect the menu itself, in case the entry gets unpinned.