The V-Groove Exterior Overcut controls where the Blade Retracts from the Matboard (not the Fallout) on the Exterior cuts of the Outside Cut of the Non-Oval V-Groove.
The Exterior Cut is where the Blade Plunges or Retracts from the Matboard (not the Fallout).
If the Exterior Overcut on the Outside Cut of the V-Groove is cut Too Long, Decrease the Exterior Overcut.
The V-Groove Exterior Overcut field is marked with a Red Arrow on the Configurations screen and the Map illustration.