For what it's worth........
I just tried a search function that worked and wanted to share.
I couldn't remember the syntax for searching for highlights. So I narrowed the search to all the highlights and entered *.* It took about 10 minutes, I've been highlighting in Logos since 2002, but it returned all my highlights, 526 Then with the power of Logos, saved it as a passage list.
Or, as many of you know, you can use the correct syntax {Highlight *} and it is much quicker and gives a more accurate result. My count went from 526 to 2972. :-) It only took 15 seconds as well.