Black Mage Umbral Fire & Ice

Hey all! I had a question about Black Mage rotation, more specifically Fire III and Frost III. I am a level 26 THM now and when I need to swap to Umbral Ice from Umbral Fire I need to cast Frost II twice in order to get one stack of the buff. One cast to clear Umbral Fire and another to put Umbral Ice up. My question is when I get all my moves, Fire III, and Frost III will I still need to do two cast in order to get the Umbral Buff when switching? Yes I am aware of transpose I just do not like wasting the lower MP cost.

no Fire III and Blizzard III remove stacks while also putting you up to 3 of the Ice/Fire umbrals.

Great thank you! I'm glad that having to cast Fire and Frost twice to get umbral rolling will not be the case later on.