Idk what OP does with their MP, but I've been regularly doing Susano EX as SCH and even after death have zero issues getting my mp back. Popping either or both LD and Aetherflow I still have MP to throw out succor when I need to and swiftcast Selene, then either drain aetherflow on Energy Drain or wait out LD timer, popping Rouse to help main healer. By 15 sec I have half my mp again. MP is a non issue if you know how to play the job.

What we need is an explosive heal similar to AST. Someone in a different thread brought up a change to Dissipation (which I don't think I've ever used except on accident) where as your fairy disappears it will throw out an AoE heal with an potency dependant on the fairy guage (on top of the 3 aetherflow gain). As it is now dissipation is just not encouraged with that guage there as it's emptied when the fairy disappears. A great emergency button and even more incentive to fill that guage instead of JUST for Fey Union (which I do love).