Clarify what you mean by backwards growth for myself and the future replies.

I say that yes of course the proper posture will be able to reverse it; I just feel depending on the specifics of your case that you may need to get a bit more of a 'jump start' to the forward growth than your peers may need. 
Perhaps you *need* NCR whereas others just benefit from it? Perhaps facepulling is a little bit more recommended in your case compared to others?
That is my emphasis.  Perhaps it just requires additional efforts on your part, yet the end results should be comparable.

What do I know of backwards growth that you speak of? So little. I'm not even sure what you possibly mean.
Not trivializing here -- its just in order to see where you are coming from I have to imagine that the upper palate is further back than the mandible thereby making it more akin to a variation of Class3. 

Unless 'backwards growth' means the formation of bone along the suture in a way that it expanded towards your airway?
....Pardon my need for clarification.

point is
Yes. Yes. YES. YES i say that your journey is capable of wonderful results regardless of the previous conditions.