Can anything damage the UGLI™ hybrid’s Cardboard case?

Yes, of course it can be damaged. We do not recommend poking a hole in the case, or cutting though the cardboard with any sharp objects, or dragging it across the ground, or hitting the case with any sharp object as those things will result in “cosmetic damage” to the UGLI™ hybrid’s case.  However, those “typically” should not, unless severely abused, affect the oven’s operation in any meaningful way.