I don't know about autonomous, but they did use it for driver feedback. Their loader just an arm that rotated upwards, and as it went past vertical the tetra fell onto the goal. That made it important for them to be lined up with the goal, and they had two different sensor systems to verify that.
I'll do some looking and see if I can't find the team number or a picture of the robot.
{Edit}
I found a picture, but no team number.
The mag sensors are the black and yellow boxes down low in front, and you can see the camera near the top in the middle. Their arm just pivots around the shoulder joint and drops a tetra on top of the goal. They were able to stack 6 on the center goal in two minutes at the
DC Scrimmage .
Wetzel