So here's something I've been playing with.
I don't like the Traditions as they exist, I think they're to big, even for big groups. I also think as they exist undermines the Traditions flavor of being about freedom but chaotic vs. the stolid well defined Union.
So rather then having Nine Traditions, the traditions have a council with Twenty One Seats, and the seats are voted for by the Masters.
Why Twenty One? To distance ourselves from the stupidity of attaching seats to Spheres, which was just awkward. I also wanted enough seats that a few smaller collations might hold one or two. And I wanted it to be obviously a bit too big, to unwieldy.
How do you become a master? Politically complex, though if you have both high enough Arete and mastery of at least one sphere it gets much simpler.
Some groups are big enough, organized enough, that they always get a seat. The Akashic Brotherhood, Euthanatos, Sons of Ether, Order of Hermes, and Virtual Adapts all manage this.
The shamanistic collations USUALLY can agree on enough to get one of there own up there, though there is no 'Dreamspeaker' organization.
There is usually a Christian, Muslim, and Hindu mage on the council, though which group is ascent within those deeply Sectarianistically divided groups changes often enough that there's little in the way of political continuity here.
One or two other groups also have enough support to be permanent members on the counctil, but the other seats rotate and shift on populist whims.
There are a few mages who command enough personal respect to hold seats on their own long term. One of the students, or students of the students, of Sh'zar has sat on the council since it's formation out of respect for his work creating the Traditions.
Mechanically, rather then choosing a Tradition and getting a favored sphere from that, you simply choose a favored sphere. You also choose your 'flavor.'
Revelationary mages talk to invisible forces beyond the veil.
Technocratic mages makes things and use tools. Alchemist and and astrologist can fit just as much as a wielder of iPhones.
Estatic change or control there own perception and feelings to control the world.
Paragons simply master skills and techniques to a level lesser men might think miraculous.
Ritual Mages use ceremony and pomp to command the world.
Intuitive see deeper and walk among mystery.
Mages could spontaneously invent and cast rotes from their own 'flavor' and paradigm, and simply pick up and use any paradigmatically appropriate foci. They would have to learn (spend experience) on paradigmatically appropriate foci outside their flavor, or within their flavor but outside their paradigm, and the same for rotes. For things both outside paradigm AND outside flavor they would have to pay twice.
Basically, you can get your Etherite friend to teach you how to use their laser gun, but it's hard work if you don't think in turns of guns, and light is a force of revelation and truth to your mind. But it's a bit easier if you're already fastidious about taking care of tools, and you understand careful maintenance and following direction.
At various Arete breakpoints, you would pick up another flavor. Probably at 4, 7, and 10. At 6, 9, and 10 you might learn to think in another paradigm.
The Hermanic has summoned and commanded spirits for so long he starts hearing their whisper and can casually bargain and deal with them. He's gone from being a Ritual mage to also Revelation. After bargining with spirits of this and invoking angels of that, he has started to get the Virtual Adepts. He might not be fond of computers, but the basic informational nature of reality... yeah, he's behind that, and he can write books tell stories that memetically twist your world asunder.
Going from Arete eight to nine would involve some sort of extra quest to make it harder, and again going from nine to ten.
From ten on, I would barrow somewhat from Awakenings Archmagery, with each level of Archmagery getting harder and harder to unlock, involving turning inward and creating your own inner world, walking to places abstract and conceptual even to other mages, but it would also further burst open your paradigm and flavor. At Archmagery 2 you discard flavor entirely, at Archmagery 4 you have no paradigm.
At Archamagery 5 you ascend of course. We don't need level 10 spheres thank you very much.