Two types of midi data:
1.Sysex= System exclusive.Although it's cool to be able to control the exclusive parameters of a HW device it's not at all necessary.
2. System Common data+ that data that is common to ALL midi devices:
A. note on/off
B. program change
C. etc.
If you insert a VSTi into a slot of BIAB, Biab is sending all the normal system common data for that channel.Just look in the midi monitor.So Paul if you've coded your VSTi correctly it will pass all the system common data.If you insert it into the DEFAULT slot it'll pass all system common data from all channels.BTW BIAB does not send any System Exclusive stuff.RB can be set to though as long as you program it in.