Short update: I have come to realise that Moode has an internal playlist management system (I can actually see it in the gui). In previous iterations of my setup, I always needed an app to be on (not closed by power saving systems or the phone being off) to retain and advance the playlist, or make use of BubbleUpnp Server to wrap it as an OpenHome device.
I just found out Moode is already wrapped in an OpenHome configuration. This solves my issue.
I just found out Moode is already wrapped in an OpenHome configuration. This solves my issue.