This is what I do also. Works for me.Keep feeding until they have drawn out two deeps or until they stop taking the syrup.
When you add another brood chamber or a super, do they usually move the stored food up?A dissenting voice here: Keep feeding if you want feed in your honey, especially if you are running 2 deeps for a brood chamber(more places for feed to hide ). If you fill them with feed, where do you think the feed goes when you add a super and the queen needs room to lay eggs?