I'm unclear on what "the soft play-thru of audio from input devices" enables.
I would like to have one microphone input work in two applications simultaneously. (To, for example, record audio while using dictation).

Similarly, I'd like to route audio playback from one app into another, live. (Again, in my case, to play recorded audio notes into the dictation app.)

Does SoundSource provide either of these functions?

Thanks,
Paul