Followup to >>336068309 , here's a voicemeeter potato setup for routing real instruments and your regular headset microphone through a DAW and back into vrchat mic input. The crux is again making sense of potato's bizarre signal flow, this time with the "Composite" "mix mode".

For the 3 WDM virtual inputs voicemeeter provides, it additionally provides an ASIO "virtual device" corresponding to each, which a DAW (in this case bitwig but could use reaper or whatever) can then use. Normally when you send a hardware input in voicemeeter to a virtual output (B1, B2, B3), voicemeeter will mix the two devices together. However, if you use the "composite" mix mode", then voicemeeter will instead keep the tracks on separate ASIO channels, which you can bind in the DAW separately. The ASIO outputs are implicitly bound to the voicemeeter "virtual input" section, which you can then send to both the hardware output (index headphones) for monitoring, _and_ a different voicemeeter virtual output, i.e. a microphone that vrchat can bind to.

So in pic related, I have my index mic and piano as hardware inputs into voicemeeter. Those are routed to B2 aka "Voicemeeter AUX ASIO" in composite mode, whicha re picked up by bitwig as "Stereo In" and "Mono In 2". I have a dumb sidechain ducking so my loud piano action isn't picked up by the index mic, but obviously you can do more here. The mic and piano are mixed to a single Studio output by bitwig, which corresponds to the "Voicemeeter AUX" virtual input. Which is then routed to my index headphones (for monitoring) and to B1 aka VoiceMeeter Output in windows, which goes to vrchat.

At the same time, vrchat and other windows audio goes to VoiceMeeter Input aka Voicemeeter VAIO, which is routed by voicemeeter to the index headphones.