The only purpose the Primal spells have (aside from extending the life of this shallow content) is to make you feel bad for not having them because aside from the 5 star spells Blue Mage has no other off-gcds besides Off-Guard and Peculiar Light (which have castbars for some ungodly reason). They have neat animations but they're otherwise the equivalent of having to farm ponies to be able to use Fleche and Contre Sixte on RDM.