[LongMan]

I assume that you are running a Jellyfin Server on your network.
You can continue to use CoreELEC or LibreELEC, either is fine.
 

• Install Jellyfin Kodi or Jellycon addon and enter your credentials.
  
• Install the Jellyfin client on the device (phone) you want to use as remote control.
  
• That may be restricted to android right now, not sure about the ios client.
  
• Open the client and connect to Jellyfin Kodi/Jellycon using the 'cast' option.
  
• Now any item played on this client will be play on Kodi.
  •  (NB: nothing plays on the phone while it is connected)
    

You have access to all the features of Jellyfin available in the client. If the Jellyfin client can create and manipulate playlists then you have access to that. Just connect when you want to play or even after you have started playing.


Hope that helps.
Cheers,
LongMan