The goal here is central media management for the whole home and you guys are literally ONE feature away from making people throw money at you!
Plex offers most of the core features people want with Premium Music and the Android app is surprising responsive, it’s almost ideal. Plex has the centralized management, it has wireless syncing to your phone, it has web and desktop apps with content scraping, but it has no way to share playlists. With that one addition Plex would position itself as one of the best unified media management solutions around and it would potentially draw in a lot more paying customers. Having Plex manage all your media in one place would make the product significantly more compelling and it should at least sell more mobile apps, but almost certainly result in more plexpass subscriptions as well.
I think a straight forward way would be something like Public/Shared and Private playlists, this way users can access a managed set of playlists and ideally even contribute with varying editing rights. You could also set if users have access to global playlists in the plex user permissions. It should be pretty simple that way. Ideally we could set read only or write permissions to some users which would allow them to edit one or more global playlists.
Video playlists are an ok feature to have, but people really want playlists for music and so to get people to see the full potential of the Plex Music platform they need a way to share or import/export playlists. That’s really a holy grail level missing piece to the platform. We can look around and see playlist sharing is very popular, so it’s very much an on target feature that appeals to music lovers. Since you have the Android app you may as well leverage that coding investment and make the system truly viable for the target audience of local music collection fans. It just makes sense!
At the end of the day I don’t care how the playlists get shared, but I need at least my managed users to be able to have access to playlists that either the admin creates and manages or rights can be assigned for group management. It would really make Plex awesome.
Some way to import copy and pasted or m3u playlists would also convince at least thousands of people to use plex as the home/mobile solution. There are plenty of app sales on music apps on the play store from people with large local music collections they are not willing to give up and some have spent tons of hours making those lists, so I’d highly suggest making some kind of import option beside itunes, which is overly complex. Since music users are more likely to require app use, they will be among the most likely demographics to pay as well 
It’s the fabled ALL WIN scenario. We must make this happen!