Completed the grid and was then stuck, until I saw the hint on this site to google a couple of the reviewable solutions.
Confident that I have now completed this challenging and enjoyable puzzle.
The only loose ends are:
1) several clues I am unable to parse (too numerous to list) and (2) I don’t understand the reference to two titles overlapping, and indeed I was unable to use some of the extra words.
Happy to wait 3 weeks to clear those up.