The satellites are presumably themselves beamforming their transmissions to the dish to a high angular precision. If the satellites know their attitude precisel

The satellites are presumably themselves beamforming their transmissions to the dish to a high angular precision. If the satellites know their attitude precisely via star tracking and IMU, then a single satellite could be enough to geo-locate a dish. I wouldn't be surprised if SpaceX tracks starlink satellite orbits via GPS, so that may limit their use as a redundant GPS system. Now I'm curious what their command and control links look like. It's possible and perhaps likely that they can only communicate with any given satellite intermittently, as they fly overhead of ground stations.