D’oh! I tried what you described before but forgot to set the remote control volume buttons to the Roku emulator. Now it works controlling DSP volume and combined with this explanation: Device volume control on where the DSP volume happens I think I (finally) understand 
Thanks again for a very clear and detailed answer.
I have one more question about running the extension on Windows as a console app. Is there a way to make the script run in background. Right now I have an open console window running that I minimize but could this run indivisibly?
When I shut down my Windows computer at night I like it to be like an appliance so I just push the power button that is set to shut down Windows. I don’t close the Deep Harmony script first. Is this bad for the app or process. Can I accidently corrupt something that way?