[Suggestion] Use exponential volume scale
I recently noticed how oddly the Astiga browser player interacted with pulseaudio's sink input volume. Intuitively, I would expect midpoint of Astiga's volume control to correspond with 50% sink volume, but currently, I need to set Astiga's volume to around 1/5 to get 50% volume.
The problem seems to be that Astiga uses linear volume scale. This results in a volume control that is too sensitive at left end and nearly useless at right end. You can read more about this here:
or for a simpler discussion
I don't know what library you used for the music player, but you can fix this by applying an exponential function or just x^4 to the UI volume as described in the first link.