I modded it, as the ending of the guitar on the pianotrack was the cause of the only 2 bar note sustain (See picture 1 below of your SGU file's ending). Modded the SGU by removing 2 bar endings and creating a tag, only then you'll have a singe note on the pianotrack then. (See picture 2 below, tag fix see next post).

You'll have to edit the style =BILLY (piano track set to guitar-midi GM voice) to fix that if you want 2 bar endings to work.

Dropbox download moded file: CustomFit165E%20modded.SGU?dl=0

Attached Files (Click to download or enlarge) (Only available when you are logged in)
BIAB ending Billy.jpg (198.27 KB, 64 downloads)
BIAB ending Billy2.jpg (255.07 KB, 64 downloads)