Heres my methodology with biab.
Might help someone.
(when I do an upgrade of biab eg 2020.)
Step1. I audition every single instrument/noise/drums/
Song demo/midi ie EVERYHTHING in biab.
Takes a week.
I’m looking for IMPACT and SOUND PICTURE.
The ones I like I save in a FAVS folder.
Step2. I build/assemble my BACKING BANDS from the FAVS FOLDER.
Rather like in the old days motown and muscle shoals
Had their in house backing bands ready to go.
i usually end up with FAV 50 backing bands in a separate
MY BACKING BANDS FOLDER SEPERATED BY GENRE.
Step3. Start writing songs , using the backing bands folder
Loading into biab the backing band I want for a certain song
I’m writing. And away we go.
then i xfer all the tracks into reaps.
going back and forth as needed tween biab and reaps to add
or delete or massage tracks.
step4. i add my own instrumentation and vocs in reaps
depending on what the song calls for.
THUS biab for bed/backing traks. reaps for vocs/overdubs/
edits/moveing things around/trickery.
Et Voilas mes cheries lol.

my songs....mixed for good earbuds...(fyi..my vocs on all songs..)
https://soundcloud.com/alfsongs
(90 songs created useing bb/rb)
(lots of tips of mine in pg tips forum.)