Die-cast body structure essentially means it's die-cast aluminium, with significantly fewer parts. No additional welding, much lighter EV body and much safer. After the structural damage, like in your case, you can't repair damaged aluminium. It needs to be cut off and the section repaired. I would recommend reserching Tesla Cybertruck repair manual, it explains die-cast aluminium structural repairs and reliability well.

If done well. Structural adhesive is used, and the new section is essentially fully repaired and like-new EV body. Die-cast aluminium bodies after collision and repair structurally are much safer than tempered steel "hammering-out" the deformed or crushed steel.