I tend to keep GB on throughout dungeon and raid runs unless the fight has such a high movement/dodging/kiting requirement that it becomes detrimental so I can't help you with that question because I do not follow that rotation and I do not turn off GB for rotation purposes. I only turn mine off when fight mechanics aka things like the AoE's and movement are too complex to keep up a decent level of DPS with it on. In those types of fights I master weave and have no set in stone rotation to begin with until done that same fight enough times to pre-plan everything without worry of major mistakes.