Curiously padded spells

With a new saga in the works, I've been getting some new players to create Magi, two of whom want to play about with illusions, though in very different ways. Reading through the sample spells, there are some curious inconsistencies. Specifically, Veil of Invisibility includes a +1 magnitude for the changing image, as do Silence of the Smothered Sound and Wizard's Sidestep. Taste of the Dulled Tongue, Illusion of the Cool Flames, The Captive Voice and Image From The Wizard Torn do not.

Why? Is this a legacy effect, trying to keep these spells to the same levels they were in prior editions? If so, why bother, when do much else has changed? Is this to balance the effects? If so, it doesn't seem to manage it, since it only actually seems to apply to spells which could be used in combat. It's also inconsistent, both between spells and with the setting assumptions. Adding magnitudes for CrIm makes sense, as the image must change. Once a ReIm or PeIm spell moves the species of an object or stops an object emitting species, the movement of the thing shouldn't affect that anymore than a CrIm to put a pink dot on a sword should be affected by moving the sword. If the designers wanted these effects to be difficult, then the guideline should be a magnitude higher. Spells which end when touched are fine, but that's a special, non-standard duration as things stand. Quite a good one, too, and a nice target for original research.