Too much spell speed for BLM?

[IceSpear]

Hello forum readers IceSpear here and a question came to mind while a Scholar had Selene out and I was doing my AoE rotation. When Selene used her spell speed buff it seemed that I was missing a few umbral ice ticks or more practically I was casting my spells too fast. So this begs the question, is there such thing as too much spell speed? Sure this is an AoE rotation, but what about single target rotation, could too much mess up your umbral ice phase.