Bubble deck, has anyone actually done one?

So there is a (now decades old) concept where you design a flat plate concrete structure where they put plastic balls in the middle a two way slab. Basically you can design a 16” slab that weighs as much as a 9” slab that has the strength of the 16” slab.

So has anyone here actually designed one, or is this one of those ‘cute in theory’ systems that never makes it past concept?