One thing to consider is the AoA should be measured from the perspective of the airflow and not assuming it's parallel to the ground. I found this image a while back. IIRC, that airflow is about 5 degrees coming off that roof line and the higher you mount the wing the less angle to the airflow. So your true AoA where you have that mounted is really more like 9 degrees. Though it may look odd, to get 4 degrees, your wing would actually be pointing up. I have my wing set level to the ground.
