One idea I've decided to go with:
The Grand Tribunal is much like a convention or conference for the wizards of Mythic Europe. Its one of the few places people can get together and talk shop.
To that end, a series of seminars/symposium-type offerings will be put forth with a schedule.
These workshops, dialogues, and brainstorming sessions are overseen and taught by the finest wizards alive, and add greatly to Hermetic reputation.
In game terms, there is one major and one minor symposium. One gives 8 experience points in a selection of arts/abilities, the other 5 (these numbers I just came up with, but I very much want the Grand Tribunal to be a special event).
The catch is, you might not get what you THINK you're getting out of the Tribunal's symposium series.
A seminar advertised in the schedule as "Tytalean War Magic", might really be a bunch of older Tytali who get together year after year to drink and talk about old war stories. You might get points in Tribunal Lore, and a few points in penetration. Others might increase your reputation and prestige, but not really give out as much in the skill department.
Some will be dead on. Others will require some quick research and appropriate rolls to determine if the presenter of a seminar is REALLY worthwhile.
On another level, the attendance of symposiums, seminars, and workshops will be a political game among the higher ranking wizards. If no one attends your program, perhaps you will be frowned upon. Wizards may try to snub their rivals and dissuade younger mages from attending their seminars. Indeed, how voting may go may be roughly gauged by who among two rivals attracts the greatest attendance to their seminar.
And the solitary magus who is the only person to attend a workshop with a snubbed mage may receive something they didn't expect: a copied spell, a pawn or two of vis, in the hopes that word will spread of their generosity to their temporary students and attendance will increase next time.
THAT said: As I love to brainstorm with the folks on this forum, I thought anyone who might want to propose a mage-teacher, the name of a seminar/dialogue/workshop/symposium, and some possible allocations of experience points or other rewards that might be gained from attendance.
I'm also planning on working these seminars into a larger, over-arching plotline... but as yet details are forthcoming.
SO... add any ideas you like to the Grand Tribunal Symposium Schedule! I'll post a few of my own...