I know I am coming into this a month after conversation ended, and to that end I am sorry.
I wanted to add some other view-points and suggestions to the conversation. One of my buddies was also quickening at Origin's. He only quickened health spells for people. His character concept is a support mage, so it fit with his archtype. Here are a few things that we encountered.
Sustaining: Trying to sustain spells on the other 6 people at the table adds up, quick. -2 penalty on everything you do for each spell maintained. That usually became prohibitive enough that he did not want to have 6 sustained spells out there at once. Sustained spells do not last game to game and therefor was not an issue going from GM to GM.
Quickening: As a downtime action, where you must buy hits, most mages aren't going to be able to hand out spells with 4 hits, unless they are specialized in it. He also made sure to mark down all of the numbers needed for getting dispelled/disrupted. Another thing that came up with having the quickened spells is that his SIN got checked regularly (At least once per game). {Watcher spirit notices lots of spells with his signature, tells mage, mage calls patrolman, patrol checks SIN and Licenses. As a side effect of having one of his spells on you at the time, the rest of us often got checked as well.}
Also, there was a mission that had us going through customs. He had licenses that were not recognized at the place we were going to, so he was given the option of getting new licenses or having his spells dispelled.
The 3rd way that the quickened spells were dealt with was in a combat where none of the magical people wanted to look astrally. There was a mage that was staying astral and just knocking spells until they faded. (On tables where they don't have a mage or the mage doesn't want to defend the astral, this could be very problematic.)
We at the tables accepted these as fully reasonable ways to deal with having multiple high force health spells quickened on the party.
For the gamebreaking of it, we are all experienced players and wanted the new players to have fun. We would give the new players the spells/sprites and let them shine. Our glory was in the ability to boost. (and with the pre-gens not being updated to fit into NT, we had to find creative ways to have the new players shine)