Hello @Ljroll28 and @stadman,
Thank you for reaching out here in the Community!
You can use your existing account and change your subscription to Premium Duo. That way you won't lose any playlists or follows and stats, it's just the subscription that changes.
Other members can also join your plan with their current accounts and keep all their libraries, or create new accounts to join if they want. If they want to keep their current accounts with their libraries, they need to remember to log into their own account to open an invite, and not create a new account.
More details on how to start Premium Duo subscription and how to invite other members can be found here.
I hope you'll find this helpful!
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