Can qpwgraph be used to control the volume of a sink interactively?

I'm using qpwgraph as a GUI to manage audio streams, but I don't see how to control the volume interactively through the GUI itself. Example: I can send audio from a browser to both my headphones and to a browser instance of Discord. To be able to control the headphone and Discord volumes independently, I can create a virtual sink with output to Discord, leaving the default sink with output to my headphones, and then use wpctl set-volume on the command line to the set the volumes. I would like to be able to set the volume interactively through, say, a GUI slider rather than have to use the command line. Is this possible with qwpgraph? If not, is an alternative to qpwgraph that allow for GUI management of streams AND their volume?