Many, many, many years ago I wrote a Lua script for StrokeIt that would allow changing the system volume.
Since then, the script has stopped working, and I stopped maintaining it. It had some dependencies that I didn't bother to keep up with, and it required some user editing of the script to get it to function as intended -- not exactly the most friendly of experiences.
Today, I decided to re-write that functionality as an actual binary plugin for StrokeIt, and release it as open source.
You can find the repository here: https://git.sdbarker.com/sdbarker/strokeit-volume
You can find the binary release here: https://git.sdbarker.com/sdbarker/strokeit-volume/releases
-Scott