PSA: Windows 11 has this feature build in (sort of)

[user18081972]

Duplicating the audio isnt possible.
But simply rerouting it to another device can be done using the audio mixer:

Just click on the process and it will show an input device selection dropdown

[GarfieldGod]

However, clicking through the Volume Mixer is too many steps and cumbersome. Are there alternative methods to automate this using the command line or other means?
For example, something like:

AudioRouter.exe <Progress> <Device>

Which would set the audio output of the specified program to the designated audio device.
If this can be achieved, it would enable many awesome derivative applications.