Handling long-running required loading task before playback with a MediaLibraryService

I've been attempting a full architecture of my music app's background playback service to use media3's MediaLibraryService. However, my app requires an extremely time-intensive loading task that must be completed before any playback can start, which leads to a large amount of issues with attempting to integrate the current architecture which is seemingly designed for only streaming use-cases and doesn't have any utilities to accommodate this type of process.

My ideas:

• I would try to couple the loading logic with the new service, but this requires low-level notification control I am unsure is feasible with the API given by MediaLibraryService. MediaNotification.Provider I assume is just called whenever the MediaSession itself changes, and is otherwise basically impossible to trigger or control in any other circumstance.
• I could try to spin off some long-running task with WorkManager, but I have no idea how feasible that even could be since it would mean attempting to start a foreground service from another foreground service. Additionally, I would still need to have a placeholder foreground notification within the MediaLibraryService, which is both ugly and still requires low-level notification control.

Would either of those work at all? Is there any part of the library that would allow me to handle this easier?