Charlie,
Thank you.
this is not about porting to DAW or controlling them in sense "riding" things in live studio rig.
I want to audition select realtracks and compare with midi tracks from imported midi side by side, before rendering tons of wavs, going back and forth between programs.

As I mentioned, it is possible in BIAB (tested!) but very cumbersome. The logical and smart thing would be to open up BIAB mixer to make it more versatile for real tracks and midi.

If this happens, the simplest way would be assign one stereo mixer track as a BUS for monitoring things that come from VST. Get the sound you are after and then render/export to individual wav files to do the mixing in DAW in one step.

I think it is a better approach than involving hardware or exporting huge amounts of data per song just for auditioning purposes. I guess if it is not there, it is a valid item for feature request.

Misha.