Hi PG, glad to hear you're doing well - good luck with your impending delivery.
Andrew, I was also wavering on the highlighting. After adding the extra letter, 14 cells jumped right out at me, leaving 9 to go; just the right number for the singular form of your TV program (wouldn't that be programme to you?). I finally decided that "illustrates" from the preamble meant a visual representation of the "origin." But, if I have it right, I'm somewhat unhappy that the "final unclued entry" is also part of the illustration. I'm not sure why that bothers me, but it does.