Usecase: Node edit form

-Group field_1 field_2 in a mini panel mini_1
-Add mini_1 to the panel content
-Add field_3 to the panel content
-Add Node general form to the panel content.

The idea is to have, for example, field_1 and field_2 as a mini panel in one region, field_3 in another region, and the rest of the fields in a last region.
Panels does detect that field_3 is already rendered, and removes it from Node general form. However, it doesn't see field_1 and field_2, therefore these fields are duplicated in mini_1 AND node_general_form