everyone - I'm retracting my assertion that there is an extra thematic item, as I was taking "standard crossword directions" to be horizontal and vertical, which of course they're not! Right-to-left doesn't work and neither does bottom-to-top! I think in my fit of indignation I was determined to make a point, and sadly, as I still think this is a very poor "requirement", I failed with that one! (For those that are still wondering what my (feeble) point was, I was looking at the first letters of the clues.)
I still maintain that "11 letters, in standard crossword directions" should mean one thing or another, not both, and this highlighting requirement adds nothing to the puzzle other than some annoyed solvers!