Several cold war bimbo programs tried to improve on the basic structure of bimbos, often with mixed success.
Take this Eastern European model for example. While it’s point of origin can’t be determined exactly, the attempt to increase the hip to bust ratio by reducing the intervening mass, has accomplished it’s goal, but not without consequences.
With so little support, a permanent structure needed to be added to ensure structural integrity was maintained.
While this was acceptable for some, the majority of targets of the cold war bimbo programs found this to be off putting. Therefore these kinds of extreme structure changes were not very common, and always limited to those bimbo’s destined for private service instead of public.