The version of shairport-sync being used is now almost 2 years old. There have been a lot of updates since version 3.0.2: github.com/mikebrady/shairport-sync/releases . A lot of improvements have been made: Better volume level continuity, Better AirPlay synchronisation, Much faster termination, Added or improved compatibility etc.
It’d be great if the shairport-sync package could be updated!