Yes it defiantly needs that !
You can open the SGU in C:\bb\BBPlugin\Files\Band-in-a-Box DAW Plugin Standalone.exe
In C:\bb\Data\bbpluginchords.txt this will allow custom voicings
Quote:
; This file allows you to set voicings for the block chords used when exporting
; chords as markers. The file bbpluginchords.txt should be used only by PG Music.
; You can enter this on a single like (without the quotes) 'CMaj = G,C,E'.
; The first note will be the bass note (ie: C/G). Do it for the key of C and the
; program will automatically transpose it for all other keys.

; Separate notes with a comma ','.
; Any line that does not begin with 'C' will be ignored.
; Valid notenames: C, C#, Db, D, D#, Eb, E, F, F#, Gb, G, G#, Ab, A, A#, Bb, B

; Here's an example that will set all major triads to be in root position.

C = C,E,G