You can use 2 Plugins to get over 255 bar limit but there maybe a way to do it natively now it's playing the track data direct.
bbw2 does that for Realband.
More bars would allow the Plugin Standalone to be used as a Live Arranger generating up the different chord sections for the chosen Style then being able to smooth seek to the bar of Midi imputed keyboard chord.
If it's used as a DAW Plugin the played sections can be recorded then transferred into the DAW as the song.