I don't have any good suggestions regarding macros, but you could also set it so that holding L2+R2 or R2+L2 each brings up another half cross-bar. That doubles the number of skills you can access without needing to cycle between bars.

Also, you can select which bars are included in cycling, so if you do need to cycle bars and are only using two of them for combat skills, it should just be a single R1 click to toggle back and forth rather than "have to switch it two MORE times to circle back".