Noel,
Thank you for the reply.


It is possible, to have it semi-independent.
Arrangement is on melody track. I solo melody track, and all channels from H.S. will play on that melody track and can independently tweak Halion tracks.
+ choose, for example real track bass from BIAB mixer and soloing it too. Both will play. I can audition two at same time or chose either. So to make a point, it is possible, but very clumsy and not intuitive. So that is one way of isolating instruments, so they play independently.

With this post, I wanted to know if there is a simpler way of doing that.

The only true solution to this (and far not only to this) would be open up mixer to 16 Midi channels.

Or simple and dirty method, to have what I described above happen in more logical workflow.

P.S. BIAB would render all tracks on its own mixer + the ones on the VST, except for original midi drums from midi file. I successfully rendered 11 tracks in one "render" operation.