DPS-wise, I agree with you (and everybody else who has posted). That's what I do as well. I spec FoN + HotW and treat the fight as mainly single-target.
My question was regarding aggro, however. What used to happen on our initial tries is that because people were spread out, I would pull some of the Reflections before the tanks got the chance to, pissing them and the RL off.
So I was contemplating whether it would be better to glyph Guided Stars or delay using Starfall when self-reflection is cast but both of these options would result in a dps loss. We've now amended the tactics to stack up on the boss and AOE Reflections and Corrupted Fragments so hopefully I can return to using Starfall as normal.