RPM Invisibility rituals

[qchap]

Originally Posted by Christopher R. Rice

General note on transformations is that for most of them that are beneficial you use Altered Traits. For transfigurations like turning someone into a toad - you don't.

I know it, but turning anyone into a frog is basically winning him in the fight. Why is it cheaper then to impose any other disadvantage, like the said Blindness (if I am right and you need Altered Traits for Blindness, of course)? Is it only because of how bothersome would be to calculate templates?