If the pieces are > 8' long then you must manually edit those SketchUp components and split them into several parts. You'd have to do it to the DXF files too [in CAD] ?? There's nothing that's perfect - as far as I know ? Does CutListOptomizer do it [orthogonal?] ? https://www.youtube.com/watch?v=kbfnTOzh7_4 https://www.mynesting.com/ might process DXFs of the parts ? https://www.maxcutsoftware.com/ ?? I'd expect that some CNC software does that optimizing as a later step... But these will assume orthogonal too ? With complex curved shapes like your ribs, then manually locating and rotating them onto a simple 4x8' sheet 'template' underlay component, locked in place, is still likely to be your best solution...