Speaking of "really huge" - Culture Orbitals are about the ideal: ~3,000,000 kilometres across, 1g at surface and rotation time of 24 hours so no need to stuff

Speaking of "really huge" - Culture Orbitals are about the ideal: ~3,000,000 kilometres across, 1g at surface and rotation time of 24 hours so no need to stuff like the shadow squares of Ringworlds. Sadly, they do rather require "magical" technology....