I have tested the Kodi addon. It is actually not as easy to install compared to Raspotify since it still requires you to install other stuff. To be honest, I stopped and simply switched back to using Raspotify.
The solution LibreELEC is offering is the nicest. If Raspotify can be added to the OSMC Store, that would be awesome. @sam_nazarko mentioned a “how-to-create-OSMC-apps” page would go online but I haven’t seen it yet. I would say 1) add Raspotify to the play store and 2) in the meantime, work on a fork that allows you to stop Spotify Connect playback in OSMC and preview song title.