I have a large body to print. Logic says make it hollow to reduce time and material. But it doesn't work. Even though volume is much less the hollow creates more 100% infill surfaces and the weight is about the same as fully printed.
Tried making 2 concentric cubes and print one at much lower infill and cannot then one. You can print the internal at a much higher density but not the other way around.
So my request is to allow lower infills on interna volumes in order to reduce weight and print time.