In the USA it is illegal to put an ADS-B Out transmitter on a drone; is that the case in Australia as well? Being visible to ATC and those with ADS-B In would seem a higher priority than filing paperwork. Alternatively, having ADS-B Out required for all manned aircraft and requiring ADS-B In on drones along with evasion software would satisfy the need for separation without burdening the ATC with drone tracking and the drone with a battery requirement for the transmitter.
Given that a drone will typically have an omni-directional transmitter to send back video, and that frequency space is well known, adding ground tracking stations to locate any signal source in that frequency range that is above the horizon and is moving would seem technically possible. I expect the StarLink antennas are tracking with less power at the ground, all a drone tracker needs is a general direction from a wide beam receiver and a similar steered array to narrow it down.