One possible way to increase past 255 bars is to use Real Band
It has had Medley Maker since 2011 and no 255 bar limit:

Attached Files (Click to download or enlarge) (Only available when you are logged in)
2015-11-23_14-57-15.jpg (145.44 KB, 76 downloads)

BIAB & RB2024 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones