Thanks for the update and fix on the placeholder image :D
and oh! I don't know if that was there before, but just saw the "hide when paused" option for the progress bar. Thanks!
If you'd like a report on the dock, the buttons don't seem to interact with Spotify at all. forward, back, or play/pause. The song name does update and the image for "play/pause" does change if I play/pause it with my keyboard or the program itself. (Just reporting for others who might want use it)