The only thing we get to observe is the outer layer. We really have no way of knowing what is going on inside or what structures are present. The relative smal

The only thing we get to observe is the outer layer. We really have no way of knowing what is going on inside or what structures are present. The relative small increase is not in reference to a smaller sphere, but to the material resources of the stellar system. If you only need 0.00000001% of the material resources of the system to build an inefficient sphere then using 625x more is not a significant increase.