On Q&P ABers appear to use it to a limited extent .... many questions are repeated, as are answers to those questions ... on harder puzzles the same clue can be posted 4 times or more over consecutive days
But this is a positive ..... more ABers participate in this way - the site is more active
The 'Search this site' function often does not find the previous 'same question', and so its helpfulness is limited ... maybe the way the enquiry is entered is at fault or the function is poor