The grids are connected already by nested coordinates (which is the main thing required to have nested grids in ships interiors). See my exemples above. Instancing is irrelevant. Grid nesting happens even with just one player. Your location on a planet surface grid, even if you stand still, is moving in the star system reference grid. Your planetary surface grid is nested in the star system one. You do not need to experience the physics of another grid (different gravity, surface collision meshes, celestial body motion speed etc) until you transition to it or exchange info with it. Same in Star Citizen. Having said that, you can indeed also get data and info from across other grids in Elite, such as wing beacons, unknown signals, wake signals and the like. The grid connection and info exchange is all there, just at cosmic scale and different type of gameplay compared to Star Citizen of course.