Polygons should inherit smoothing group
When you create a new polygon, say by extrude, or just simply clicking an edge and shift-dragging out a polygon, it gets no smoothing group assignment by default.
So I find myself constantly extruding polygons, selecting them, then assigning a smoothing group.
It should just inherit the smoothing group of whichever polygon it originated from. In the case of a new polygon that was created without extrusion, it should get the group of its neighboring polygons.
Fractal Core commented
I agree with this. It makes no sense the way it is now.