i was tought, and have read, that the best queens do have some amount of royal jelly left, but it has always been a question in my mind, they emerge head first, so how would they access the royal jelly IF, there was any left at the later stages of development? They cannot turn around in the cell, and I have twice in my beekeeping career opened large healthy looking queen cells that did not hatch/emerge, to find the queen upside down in the cell..... if they CAN reach the royal jelly they cant get out, if they cant reach it they can cut their way out..
So.. Basically, when a queen emerges, and I find a bit of royal jelly left over, I am happier than if I find none... But I do not know where the line is drawn in the sand as far as "enough" royal jelly.