I finally discovered the trick to change the ratings for ICHC, so hopefully Apple can review it now. As long as there’s a valid binary, iTunes Connect won’t let you change the ratings. If you reject the binary, you can go to edit information and change the ratings BEFORE you upload a new binary. Once you upload that new binary, the ratings are locked out again.
I set the ratings to infrequent/mild for all items, which still only results in a 12+ rating, not the 17+ rating Apple requested. We’ll see if Apple approves it now.