I did have fun with this. I worked with the timing, but never changed the mix volumes from the levels set by BIAB. I just transferred the whole mix in on one track and the vocals on another track. I never got it figured out to get the music to sync up well for the whole song, but it was a good learning experience.
I’ll attach the tracks here so you and others can play around with them.
I had my DAW tempo at 72 bpm, but BIAB did the tempo changes to try to match the vocal track.
The instruments kick in around bar 13.
BIAB Master
Bass
Drums
Fiddle
Guitar
Mandola
Whole band mix edited on original post to align some timing issues
Vocals