Currently, plasma-pa just sets the volume of the default sink when the volume keys on the keyboard are pressed. This is not necessarily what the user wants if he has a bit more complex setup.
It would therefore be good if the sink for the volume control could be configured in plasma-pa's KCM.

For example, I have this in my default.pa:

load-module module-remap-sink sink_name=headphones channels=2 master_channel_map=front-left,front-right channel_map=front-left,front-right remix=0 sink_properties=device.description=Headphones
load-module module-virtual-surround-sink sink_name=vsurround master=headphones hrir=/home/olesalscheider/.ir.wav sink_properties=device.description=VirtualSurround
set-default-sink vsurround

This splits two channels of the sound card and creates a "headphone" sink from them. The other channels could for example be connected to a surround sound system but I do not use them currently.
Then it creates another sink (vsurround) with the "headphone" sink as master. This sink computes virtual surround sound from its input signals and passes the generated signal to the master.

I have set "vsurround" as my default sink because I want all new streams to go there by default. But I have moved some manually to "headphones" where I do not want the virtual surround effect (e. g. for music).
When I now press the volume keys I want them not to change the volume of the "vsurround" sink but the volume of the master sink. Because otherwise the volume of the streams that I moved to "headphones" is not changed.

Reproducible: Always