Sometimes we may reach the point wherein we have an equal comfort level with all our feelings both "male" and "female". That point can only be defined by we, ourselves. It's a point where the feelings are equalized and we are capable of being either, both or neither. It's a point where the term crossdresser does not really apply any longer as we are dealing with ourself as a person and no longer as a this, that or the other thing. In somes cases I think it may be easier for some to objectify who they are rather than making it subjective. Of course there is always the eye of another beholder who will classify a person and say:"He(or she) is crossdressing."
In any case, I think that such a thing as ultimate crossdressing is impossible. The reason I say that is because we are either the normal garden variety of crossdresser that perpetuates the bi-gender standard either consciously or unconsciously or gender itself has been equalized for us and we are either always crossdressing or never crossdressing, depending on our viewpoint. Those who have reached this point understand what I am saying.