I have myself posted ideas in labs some before seeing the little tutorial advising the method of suggesting ideas, some were marked already suggested so the vetting process is working. However another idea which I had a search for trying various descriptions turned up no result got added to labs and straight away comment about it being a duplicate that had got past the checks. It all hinged on peoples terms what to me is a conference call was to the original poster termed 'Three way calling' . So despite all the effort taken there will probably be some duplication of ideas because the same idea can be called by different names to different people and in general people have a relatively small idea set to do with the subject. Also the missions page leading to labs does tend to encourage spontaneous posts. On the whole from my experience the duplicate ideas are mostly caught.