The Exterior Overcut controls where the Blade Retracts from the Matboard (not the Fallout) on the Exterior cut.
The Exterior Overcut field is marked with a Red Arrow on the Configuration screen and the Map illustration.
If the Exterior Overcut is cut too Long, Decrease the Exterior Overcut.
If the Exterior Overcut is cut too Short, Increase the Exterior Overcut.