pipeline,
thank you for testing! It seems that some of these midi files from vArranger have issues. But most are ok and are usable in BIAB. I accidentally turned this post another topic.... of having more channels on the mixer. Particularly in my case, an independent midi channel / bus would be very useful, which would let use VST as independent mixer. Essentially adding as many channels/ layers as your hardware would allow without interfering with real tracks or the mixer of the BIAB except maybe controlling VST master volume from BIAB mixer on that "independent" midi track.

I want to persuade people who are interested, to have a discussion and come up with something that would suit most and appeal as a group request to see if that will work. To my understanding similar individual "requests" were asked for years without success.