Master Chen’s comments:
After in-with-elbow, the next move should be that the elbow and front kua are tied as one piece and then continue with the turn. At that moment, the turning of the inside (elbow and kua) must be larger than the outside (front hand and front foot which are also tied as one piece).
On the way out after reaching the peak of in-with-elbow, the front shoulder must first open. This is done by rotating the whole arm at the front portion of the shoulder in the nichan（逆缠）fashion. At the same time, the rear portion of the shoulder (the part that is attached to the torso) must rotate and move downwards towards the floor. The two parts of the shoulder created an opening of the triangle of the shoulder (shoulder tip) from inside (armpit).
After that is done, you can continue with the second half of the circle.