Yes, great points. I doodle to listen. It keeps me from looking around. I keep my patterns simple. I got to a point where I would just tell my professors on day 1. "Professor xxxxx, I am going to be drawing a lot in your class when you are lecturing. It keeps me from getting distracted ironically and helps me do well in class."
It did not matter as I would still get called out for doing it. However, I have maintained a 4.0 all through grad school and I am convinced that doodling was the reason.