Just a different point of view
So Sponsored vs Sorcerer (Evocation/Channeling/Thaumaturgy/Ritual)
a) Sponsored gains a reserve of Fate Points independent of the Spellcaster's own Fate Point pool
b) Sponsored costs less than full Thaumaturgy plus Evocation
c) Sponsored is able to do both Evocation and Thaumaturgy within a thematic subset (which, after 2+ years of playing this game regularly... rarely hinders even a somewhat slightly creative player from doing whatever magical effect they wish... though admittedly from time to time they've been completely unable to creatively shoehorn their desired effect into a thematic/sponsored element... it does happen, just rare)
d) Sponsored gains a free boost effect of some kind (reduce Winter/Summer catch or whatever)
e) Sponsored still gains Focus Items / Enchanted items
f) Sponsored can still take Refinements*
...and... all you lose is Specializations (yes, Specializations are sweet... but still having Focus/Enchanted Items mitigates the loss)
... and if your table decides a PC controlled caster doesn't hex either... you don't even have to worry about the in-game ramifications of hexing your favorite toys and widgets. Woohoo! Fireballs AND iPhones!
Seems like a pretty sweet deal to me - both fluffwise and crunchwise.
Just something to consider. I'm not saying it's "wrong" to say Sponsored doesn't hex, far from it. Each table must choose for themselves.
With the above list, I'm just saying do consider the other side of the argument when your table makes the call. The rules support EITHER position, but I am just positing that there *is* some game mechanical merit in saying "PCs must deal with Hexing" (as a GM, leaving your NPCs free to have "fireballs and iphones")
... final point, fluffwise and campaign wise, I also posit that having "PCs Hex" is yet another reason for the PC Changeling to "Make the Choice" to become a Full Fae. To bring his/her will and Fae Nature in harmony (again referencing something the game designers put in on pg. 288) and finally be able to cast earth shattering magic and use all the gadgets of modernity again. If you choose to give that up, you lose another element of internal conflict on those Changeling character concepts. ... and really, it's a better story if "the Choice" is actually a hard one.
*Note - Officially Refinements are mentioned as only possibly taken once per spell ability - pg. 81 - the Russell Carson NPC in the core rulebook shows that even the game designers broke these "rules" (the NPC stays under the White Council's Radar, thus not white Council trained fluffwise and has Channeling and Thaumaturgy and 3 Refinements which breaks the 1 per spell ability "rule" crunchwise as otherwise he'd only have 2).