@broex
I've found another potential workaround.
Open the spotify app on your pc, then go back to the player on opera and look right next to your volume, you are able to connect to a device, choose your pc and spotify will be playing on your pc but you can control it from your player.
(my pc is called BOI)

Then just go to your pc icon tray, right click on spotify and click "minimise to tray" and you can still control spotify through opera without having the app in your taskbar!

Unfortunately, you cannot hover over your player icon and click play, back or next but for now it's a solution.

@broex
I've found another potential workaround.
Open the spotify app on your pc, then go back to the player on opera and look right next to your volume, you are able to connect to a device, choose your pc and spotify will be playing on your pc but you can control it from your player.
(my pc is called BOI)

Then just go to your pc icon tray, right click on spotify and click "minimise to tray" and you can still control spotify through opera without having the app in your taskbar!

Unfortunately, you cannot hover over your player icon and click play, back or next but for now it's a solution.