I did this five years ago:
https://www.edmstudio.com/news/faux-vinyl-experience-spotify...
https://www.edmstudio.com/news/faux-vinyl-experience-spotify...
If I implement it, I'll probably take the Linux route and use MPD/MPC on my desktop. Or maybe control Clementine through QDBus (since I use this media player on KDE anyway).
Note the video is no longer working.
If I was to do this again I’d do away with the Mac mini and use a raspberry pi plus a Spotify daemon. I still have all the cards I made but no time to figure out the physical stuff anymore.