It is hard to appease the Will Shortz God and I know first hand. I have sent (4) 15X15s to him. 2 were so-so, 1 was so-so +1 and 1 was themed very well with no problems like 'nca.' It beat many of the usual Monday-Tuesday-Wednesday puzzles he runs hands down.
All were rejected and this is where you are making a mistake, Mr. Shortz. You should give brand-new puzzle constructors a first-time 'encouragement' pass .... You have discouraged me from sending you pretty much anything now, and I have about 50 or so 15x15s sitting in my directory of which many will end up being published somewhere else.... because I'm not wasting any more stamps (snail mail in the 21st Century, tsk tsk Will) along with 3 or so months to get an email rejection from one of your subordinates anymore.
Yes, you are sitting in the highest seat and you get to pretty much choose the cream of the crop. Not only that, but you get to add your name as an editor of another artists creation, even if it is changing 1 letter or 1 clue. But by kicking new artists in the seat of their pants for decent puzzles, you are doing yourself and the craft no favors.
So, NCA author, save your stamps. If a puzzle isn't perfect to Will, you can pretty much forget it. He's pedantic (a good crossword puzzle clue for 'anal' btw).
FWIW I would kill as much of the block NCA appears in and do it over. But that's me, good luck.
-cc