It depends on the number of files/folders you have on your PC and on the way they are named. Sadly, for me the current number of search results is not enough, and from time to time I am unable to find files I need because of the limited scope.
My understanding is that Listary is already processing the whole index, it is just that the number of results shown for a specific search query is artificially limited. So it shouldn't be hard to change this behavior. But that's my opinion, let's wait for developer's answer.