> we will have no effective way of shutting off the rain of Starlink satellites

To this point, if we wanted to stop the 'starlink rain': The satellites have small ion engines that are used to enter and maintain the correct low earth orbit. Depending on available fuel, it may be possible to raise them into a significantly higher orbit. (This might end their usefulness as Starlink). At a high enough orbit, objects take decades or longer to return.

Maybe someone knows the typical delta-V these things have and how much is needed to raise an object to a typical 'graveyard orbit'.