I think there's a roundabout way to go about doing that. Essnetially create a lot of additional voice VFO's and then set each one of those VFos to have only 1 talk group with its priority set to 1. And then set the output of each VFO to a different VB audio cable in, then source would be VB audio cable out in audacity.
The hack RF definitely supports grabbing an entire 20Mhz swath of bandwidth that covers all the signal and voice frequencies.
Id be super curious to hear more about your setup, both hardware and software.