I am pretty sure I read somewhere that you are considering putting metadata in the cloud so that it can be shared across devices.
Please plesse bear in mind (as I am sure you have) that libraries are often shared between not only devices but also across other users who would have different iCloud accounts id’s.
I hope you can consider offering the ability to store metadata on NAS and iCloud please. My preference would be on the NAS/drive of movies etc as I believe you do for subtitles.
Appreciate your kind feedback and thoughts…