Assuming your legal conclusion is correct, while you could take the course of mentioning chocolates only on your way to secondary, it seems to me the safer course is simply to proceed with declaring it at the outset.

Chocolate either is or is not something that must be declared. If it must be declared, even though allowed, might as well do it at the earliest point possible to minimize risk. If it does not need to be declared, then doing it on the way to secondary isn't necessary either.

The problem is that CBP has not made clear whether chocolate (putting aside the Kinder Egg issue) should be declared as food or not.