I installed Nicecast and use it to capture the audio stream from Spotify. Make a radio station in Roon called Spotify, and enter the IP from the computer where Nicecast is broadcasting.
I use Spotify Connect to remote control the whole thing. Only downside is a 5sec delay get introduced.
Tidal is still my primary source, but Spotify is best to discover new music.
Spotify -> Nicecast -> Roon (running FIR filters) -> Hqplayer (running FIR XO) - DAC