But of course all features are useful throughout. You're making a point of misunderstanding and not remembering what people have been explaining to you daily for probably 10 years now....
Even the little system for turning the flight feathers, venetian-blind fashion, so that the air flows through the wing on up strokes?? Come on, PH: tell us all what purpose that could possibly serve before the velociraptor actually turned into a flying bird, or why that should evolve WHILE (as Reep claims) the wings and flight feathers were developing, all merely via mutations and "natural selection" of course...
You're stuck on this SHAZAM model in which a dinosaur turns into a bird in one day. You've been knocking it over for 10 years and you're not going to get unstuck now.
When does your feather-turning system have to appear? By the time it's necessary, it's there, because it was helpful at an earlier phase. At any given time, you're only building on what you have.
But there's no stopping you from doing strawman models based upon sheer ignorance. It's your whole game.