TOPIC: G3 aficionados, Question on the Center Deck vs. OD

I've seen some Center Deck G3's with cut out CD's, might not be wise? The later Open Deck is different with much more angle along the top from about midship to transom. A cut away view would maybe be similar to two sides of a triangle on the OD models. Perhaps this gives some torsional rigidity, just a guess though? Was the top deck change in design intentional to give extra strength because of the removal of the earlier CD? I can only assume yes but don't know? Or might you think it was done for a newer look?
ps. I've never seen a OD in person, just pics