Are you getting the edges curling up? Especially when the printer is trying to go outwards for an over-hang? Because that will result in extra material being put down and work to fill in the hole to make a less than perfect circle.

There are several reason why that happens. If the edge is curling up, when it gets pushed down it fills the circle hole more than is desired. But also, the fact it is curling up means the nozzle is rubbing against the edge and any extra material available gets put down on the print at that point. (like some extra hot plastic that is smeared near the extruder hole).