You can create top surfaces to extend the stamped part. Top surfaces are continuous with the part or with the clean contour surfaces. They are referred to as the reference surface.
From the Die Face section of the action bar, click Addendum Surface.
Select an axis system (stamping direction).
Select two vertices or two profiles on the boundary.
Click the handle on the first selected element to invert the side.
On the context toolbar, select the type of the top surface.
Linear Top Surface
Top Surface with Fillet
Top Surface with Two Fillets
Addendum Surface creates one profile on each tangency
discontinuity, and one or several multisections surfaces on these profiles.