This is exactly what I was going to suggest. RB may have the same 255 bar (or 240) problem but should be able to import or copy as many bars as you want. When i get home one test is say you've done all that, have your 327 bars and want an additional 30. Can you highlight the next 30 bars and generate? I would use the next empty track for that and do it one track at a time, not all tracks at once.

Biab/RB latest build, Win 10 64 bit, Intel 4770, 256 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.