Yes, this is exactly right. The iReal Book player has some "BiaB" like capabilities now, in a tiny iOS form-factor.
And I too have taken advantage of the "new song" capability to put in chord progressions for some of my own jazz-vocal originals too.
I can see a future version of the jazz styles pack that expands on the piano styles beyond just chord comping, maybe add some guitar styles beyond the gyspy jazz one, and maybe even some strings and horns for "bigger" arrangements.
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