More a question to see if there is a possible fix for this 1 spell that causes issues with being able to castsequence this one spell. It's also broken in wow's own macro system so i think the answer is no.

/cast Storm, Earth, and Fire is usable in wow's macro system as well as GSE.
Trying to use it in a /castsequence seems to break it because a sequence is normally broken up by , (comma's) which the spell uses so the sequence see's this as multiple spells.

Is there some kind of magic that can be done to fool the client to ignore the additional comma's on this one spell?

Statics.BaseSpellTable[152173] = 137639 -- Serenity -> Storm, Earth and Fire << also in statics, i am not sure if this is important but would the macro break on the line for missing the comma after Earth or would it be ignored by using the spellid?

Cant use SEF in a /castsequence No way GSE can work around that.