Chromecast volume control

[crazyascarl]

Is there anyway to make it so the volume slider remains active when casting to chromecast?  This is an option with Netflix, Youtube...  but not Spotify.  

I realize that over the past few months Chromecast has been changing their access.  I used to be able to cast from my Spotify desktop app, then Google made casting only available through Chrome.  At that time you could adjust the Chromecast volume through their interface, but they changed that interface so the only way to adjust the volume is via a phone app.  

Ideally i would be able to adjust the volume from the source... Spotiy.