I think what would really make an impact is if skin tight tops could be layered with fitting to loose covers, vests, sweaters, jackets, etc. Then we could still utilize existing CAS items too.
I'd love if bodysuits (long sleeves, 3/4 sleeves, etc. turtleneck, tank, etc.) were introduced that can count as full body, tops and an underclothing accessory. I'd love to layer it with some existing crop top sweaters, sheer tops and dresses.
As for short dresses, skirts and shorts, we can already layer leggings, stockings and socks—we just need it for tops too.