I do agree that based on the earlier pics, the smaller branch is the better one to keep. The larger one is just way too straight and thick. I would personally cut it off now. Admittedly I am a bit impatient and like to start shaping my trees early but as Dan mentioned, you'll get faster thickening if you leave the branch in place for now.
Also you have quite a bit of wire on the small branch. Be very attentive to it because before you know it, it will bite into the bark and often impossible to get rid of the ugly scars. Make sure you try and wire neatly at a 45 degree angle to maximize its effectiveness. Since it is a grafted tree you might want to consider air layering it right above the area. Probably best to wait to do this. Let the tree gain strength for a year or two. I would plant this guy in the ground if you can.