You may also want to look/comment on the thread I posted in the main Ars forum re: correspondences and especially bound correspondences. The more I've thought about them, the more concerns I have.
I looked at your post in the main ArM board, and I think this comes down to a difference in interpretation on what the Correspondence Rules means :
My understanding of it is that Correspondence represents an independent activity -- a "5th season" if you will -- that magi and other literati can engage in with some small benefit (+1 xp/season). Magi and other academics exchange letters to discuss pet topics that interest them. For instance, my Trianoma magus could be writing all over Europe about how life is in their covenant and pick up Order of Hermes Organization Lore as a result. This is because he would be learning the names of covenants, magi, companions, grogs and personalities of interest from the various people he's corresponding with. He will get this information from his letters irrespective of his regular seasonal activities.
For my character, what he's effectively doing is finding a theoretician and engaging him (or her) in letters that discuss deeper aspects of Hermetic Magic Theory that are of mutual interest. A RL example would be two biologists from Australia and Italy exchanging notes and ideas on the genetic predisposition of diabetes in black rats vs. brown rats, when the Australian biologist's main job in the spinal chord of white mice. It's an aside to scratch an intellectual itch.
If I understand your interpretation correctly, you're viewing correspondence rules as something that's tied to a given season's activity, so that a mage in a lab would only benefit from a Correspondence if it happens to be about what's going on in their labs. My initial take is that it would restrict the Correspondence rules to only provide benefit if both parties happen to be doing the exact same thing in the same season (e.g. both working on a Animal spell and Corresponding about their respective projects).
What I can do is leave out Correspondence until you find some framework that you feel comfortable with, then go back and figure out how it would change things. As an entirely practical matter, a magus who faithfully maintains Correspondence throughout this chargen period, they will have an extra 160 xp (or so) over the 40 year period we're providing detailed chargen for.
As a point of comparison, here are numbers of xp for post-Gauntlet 40 years:
Adventure @ 10xp/season: 40/xp per year, or 1600 xp over 40 years
Fast Chargen Standard 30xp/yr: 1200 xp over 40 years.
What this suggests is that Correspondence provides somewhere between a 10-13% xp boost over someone who does not correspond. It is some power inflation, but not overly so, IMO.
One last thing about correspondences as tractatus: The rules state that the Quality is the Sum of the two authours' combined Communication. Given that the average Communication score is +0 (by default), this will make many/most Correspondence-cum-Tractatus 'books' a relatively common, but unhelpful, resource for most magi. (Letters written by particular eloquent and expressive writers would be treasured and disseminated, much like how Abigail and John Adams' letters provide great insight into the Revolutionary and post-Revolutionary era. Such letters are uncommon, and most letter writers are much more prosaic and mundane.) There is also no 'double-dipping': the authours cannot re-read their letters for additional benefit, as they received the 1 xp/season while writing the letters.
However, as a combined resource (imagine a library with thousands of letters over an Autumn covenants' history), it's likely that someone, at some point, had notes and letters about whatever it is you're looking for and can provide an insight into where to go next. This is why a large letter collection also functions as a "research aid", per Covenants.
I would personally say that I agree with Renimar:
A Magus studies 10 hours a day. Writing a letter (still lengthy though) once a season concerning different insights into say Animal, while actually working the 10 hours on opening your talisman, seems fair. The rules of Covenants has chosen to reward this with 1 correspondace xp every season. Now - the idea that you have to correspond about your activity is probably establish so that people not only write about Magic Theory or Penetration, however as Renimar points out, it seems weird that you would have to keep check of various correspondents, who just happen to do the same as you in the same season, so you can get correspondance xp.
Unless...you say you have two correspondances...One where you write about your discoveries in what you where doing, but what you receive from your correspondent might be on Imaginem instead of Animal, representing HIS pet projects. You answer his Imaginem letter, but does not receive Imaginem xp, as you are anxiously awaiting his Animal letter, granting you xp...thus you have a double correspondance....?
This was also cross posted with Bertran, but both characters have insights that my character is interested in. As we develope all of the backstories, Hypetus (to be known as Menoetius later in life) is interested in the type of hedge magics you have enountered. He is specifcially interested in those with fertility focused powers and those that may have been developed in times past that effect lineages. Any help? Carleach can chime in as well. This is part of my failed cabal backstory.
Just bumping this here -- I'm still around, but just got very busy. I'm hoping to catch up shortly.