Hi There,
Currently when ballooning the leader/arrow head could only attach it to a edge. But in other competitor products there is the ability to attach it to a face.
The only way to achieve this now is to select an edge and then dragging the arrow head to the middle.
The problems with this method is
1. It is an extra step
2. The link is lost to the balloon after the arrowhead is dragged
I believe this is a critical feature, when parts share an edge its difficult for someone reading the drawing to figure out which item it is pointing to