I'm currently contemplating a character for a saga about to start. The maga would be a relatively normal hermetic mage, with one complication - she would, in time, likely want to have her Gift opened a second time by a non-Hermetic tradition. I know, it's madness, but that's likely what she would want in time. [I'm not even saying it's going to happen, but my characters tend to have quirks, and I always feel obliged to at least investigate their foibles.]
Reading up in Rival Magic (page 6), it seems the non-Hermetic wizard opening her Gift (again) would have an ease factor of: (2* Supernatural Ability scores) + (Art Scores) + (12, for a Gift already opened).
Am I correct that this means that a Hermetic mage, or practically any tradition with accelerated Arts, faces exceedingly high Ease Factors in joining a non-Hermetic Gifted tradition? After all, it doesn't take all that many seasons for a Hermetic mage to know, say, 40 levels in the Arts. In fact, a generalist apprentice would likely face prohibitive difficulties, even assuming a complete lack of Supernatural abilities outside of the Hermetic Arts.
For most traditions, the totals required (and that's even assuming a simple succesful opening, with sacrifice of the old Arts!) would be well beyond anyone but very talented archmages (since most don't live long enough to keep gaining experience in the way of Hermetic mages do). Succesfully opening the Gift while protecting existing arts would be laughably difficult (twice the prior total, in fact).
Now, I appreciate that Hermeticism is the focus of the game, and that it's complex and consistent system is prohibitive to any others to integrate. Yet, the real effect here is that hermeticism will have a very tough time integrating other traditions, since it will be very hard to acquire true understanding of their abilities. That, to me, seems at odds with existant lore of how things operate.
Note, by the way, that the reverse (a non-Hermetic Gifted mage joining the Order of Hermes) faces a flat +30 to the InVi lab total requirement, instead of +(Arts)+(12). This is obviously much easier, even discounting for the relative ease with which lab totals can be increased.