I found this the other day, if you haven't already seen it.
TI integration flowchart
The external audio-ins of the Virus also look like they're routed into the Virus "soundcard", meaning you can connect another hardware product (or two, if mono) into the Virus and use the Virus' to inject it into the computer at high-res.
The flowchart shows 4 x internal virus audio channels,
plus 2 x external audio-input channels, and midi controller data, can all be routed into the computer via the TI at any one time.
2 x audio outputs, and midi data, can be routed back out into the Virus TI.
Think we'll just need Access to confirm all this.