The modifier is used on attack rolls for ray of frost, shocking grasp, firebolt, and bone chill. It's used for save dc in regards to poison spray and acid splash.
This is the necklace I speak of. It allows the wearer to add their spell modifier to elemental cantrips. This is why it leads me to believe you originally don't add your Spell modifier to them. Also when I respec'ed a lvl 12 for all this, the cantrips show good damage up to 20+ damage. This is with low charisma too.
It is an interesting combination. If I get a chance, I might play with a build myself and post it here. Just my two cents.
I appreciate your thoughts and would love to see what you'd come up with.
