Thanks to Everyman.
Strange puzzle. I found most of it very easy, but struggled with a few clues, especially 17 and 21. Had to set the puzzle aside for an hour, and got 21 upon resuming.
FOI 1a, LOI 21.
Trademarks all present and accounted for.
Didn't find any really outstanding clues. Going with 20 as COD over 4d, 7, 9 and 16.