Where is my flat from Mirrored Part (Derived Component)

When I create a Mirrored Part (Sheet Metal) there is no flat pattern with it. I have to break the link and convert a Solid to a sheet metal part. This can't be the best method. Mirrored parts should be linked to both the model and a flat by default. And both parts must have a flat due to emboss direction and linked.

SolidworksSheet Metal