You can control the magnitude of the spell.
You can control the duration of the spell.
You can control the effect of the spell.
You can control the combining of spell effects.
You can even cast "trap" spells.
That sounds like the EXACT same thing as Spellmaking to me.
They are not the same EXACT thing.
1. You can control the magnitude of the spell.
No, you can charge up a spell, increasing it's magnitude, however, you have NO control over the actual magnitude of the spell. (Spellmaking let's you define whatever magnitude you want.)
2. You can control the duration of the spell.
Sorta, but with spellmaking, you can fire n' forget a spell, here you have to keep casting it to keep the duration going.
3. You can control the effect of the spell.
I assume you mean range. That's true, but, it does have disadvantages, for example, trying to cast a trap, and targeted version at the same time, might be a bit hard to get used to, or charging one, and trapping with another, etc,. This isn't the case with spellmaking, which you let's define exactly what you want to happen.
4. You can control the combining of spell effects.
Up to two, assuming each spell has one effect. With spellmaking you could combine numerous effects at once, which is NOT possible with the new system.
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All that said, I like the new casting system, I don't like the loss of spellmaking. (I think they could coexist, if the CS can do it, then there is no reason the game shouldn't be able to as well.)