TLDR: I don't see what's exactly the issue with too much college favors, since there are useful mechanics out there that do require College Favor upkeep per turn, but we might do well to take in the right circumstances. It's called a Favor economy for a reason - favor invested leads to favor earned which in turn is reinvested or circulated as expenditure. Without circulation through expenditure or investment, the Favor economy both grounds to a halt, and also doesn't grow further.
Given the fact we have a huge amount of favor sitting around and it's just going to grow with sending the Gems to the Colleges likely to win, we can probably very easily afford the 1GC upkeep of a Perpetual Master-Handler to help with our EIC Intelligence/Accountability actions, since bad rolls probably hurt our goals for the EIC, which we then have to roll again to try to fix. Plus, narratively speaking, it reflects that Mathilde has reached the point as a Grey Magister that she is starting to build a trusted retinue to help her. Plus, Mathilde is used to controlling Intelligence networks through a Julia-like deputy. Plus, the earlier we start, the sooner possibilities such as having someone to maintain and manage the network for us on our behalf once we are done building it to our satisfaction can happen.
13 College Favors this turn basically pay for 13 turns of upkeep for a Perpetual Intelligence deputy/manager (albiet one with no managerial experience, whose other relevant work experiences depends on the Gacha - we could get a very experienced operative or auditor looking to make the early-mid career jump to management on one hand, and a green as grass utterly fresh zero work experience Perpetual on the lowest end), an second IC that we know is extremely unlikely to disrupt the company culture we choose to reinforce for the EIC because the Grey College would not have given him his rank unless they were sufficiently satisfied of his integrity not to misuse Ulgu for profit. To put things into perspective, we are, I believe on our eight turn after the Expedition. Given our huge backlog and the unlikelihood, we run out of things to research, plus our Intelligence network can be used to aquire new research material if we somehow ever get through our backlog (which the Grey College won't object if they don't breach Article 9, since we are an Academic), 1GC probably is a really reasonable upkeep cost for Mathilde to avail herself of the manpower advantages that the Grey College offers considering the Room of Serenity almost certainly will yield a certain definite Favor income per turn.
A solution already exist for College Favor bloat, and indeed, I find it a very natural solution, since one would expect more experienced Magisters with large favor reserves and income to likely spend part of their income to upkeep a retinue of specialists from their Colleges, depending on their needs, of which information networks probably are the most common for Grey Magisters because of the nature of their work. I would say that availing ourselves of those opportunities really emphasizes the stature of Mathilde as a Grey Magister narratively, which so far has been limited to certain social sequences because Mathilde spends most of her time outside the College political thunderdome in Altdorf.