This is a very quick way to export tracks, even if the song is 255 bars it will still be quick without having wait for it to render down to a consolidated wav.
You can then easily edit and tweak the solo track or adjust the level or timing of a hold, change the drum shot, hold or push level or timing, add fills where you like. Nothing is cast in stone, it's all editable to exactly what you want.

This is the simplest way to use it:
Just select the BB or Util track in the floating mixer
and hit "Import Selected Mixer Track" or "Import Selected Mixer Midi Track"

Watch: https://www.dropbox.com/s/oqm12d31zovnp7q/Reaper-Biab-Track-Injector-Quick-Export.mp4?dl=0

Download: Reaper-Biab-Track-Injector-Quick-Export.mp4

Biab Track Injector for Reaper
Free Biab Chord Picker Tool