I'm honestly not aware of any Spell Speed breakpoints for Black Mage, where their rotation falls apart beneath a certain amount. And even if it does "fall apart" you'll be missing at absolute worst 1 Fire IV per Enochian rotation, which isn't gonna impact your dps substantially if you maintain Enoch, manage cooldowns, and maintain a general semblance of the base rotation.
I highly doubt you *need* a specific Spell Speed value to do any given content. Secondaries are all fluff beyond a certain point, they just give more deeps.
