What mine did, that after we got our coordination together worked, was while we spread out during the floor aoes, everyone converged on the boss after the 3 mechanic combo(floor, beam , bioarithmetic). This left us in a good position to quickly stack for the mechanic and then bolt when he used apocalyptic ray. The sad thing is it took 4 wipes for people to get the hint that the arrows mean stack... I wish I could joke about that.