If I have bought the ArM5 core book and try to find out, what those "spellcasting options" on p.82 are, I go to the index and find, that they are described in - lo - the subchapter Spellcasting Options. So they better be described there.
This makes "spellcasting options" into a term. It also prevents questions throughout a game, whether this or that or yet another ArM5 core rule define "spellcasting options" and are disallowed with Fast Casting.
It does not imply, that SGs can't add features from other, later books among the "spellcasting options" to exclude from Fast Casting.