The Vis Grant Minor Boon, from Covenants, states: "The covenant gives out a portion of its vis to each member each year as a right... This Boon is not appropriate where vis is held in common by the covenant..."
Suppose a spring covenant (entirely made up by PCs) had decided 2/3 of its "income" from vis sources to be evenly split among its members, and 1/3 to be held and spent "for the common good of the covenant". Would this require a Vis Grant Boon? Or is the Vis Grant Boon meant for (typically older) covenants where the PCs don't rule and thus can't decide what happens to the covenant's vis?
The the campaign that I am Storyguiding I did decide against using this flaw for the Covenant that the players founded.
The reason for this is that I thought that it is pp to the players as the founders to decide if they wanted something like this and how the agreement would look like. The players first diceded that: "No magus will not get any Vis until we have gathered 25 pawns of vis of each kind, but as soon as we have that much in stores, all vis we gather will be divided equally every year to all member magi of Good standing with the Covenant and the Order. " Though as they have a hard time getting that much, they have changed it two times and the current rule is something closer to 15 in each techique and 10 in each form as covenant Stores and all other vis will be divided equaly...
So by not taking that virtue, I let the players decide in their wizard's councils how they should do it and they will be free to alter their rulings as they see fit.
Afterall, they are the founders and they set the rules. I see that virtue as something an older covenant would have, spring covenants are still experimenting with their rules as they face different problems.
It's a sort of leftover of the older style of play that was common when Covenants came out, where the PCs didn't control the covenant's vis, and needed to beg for scraps. It kind of contests with the design idea that you should only really stat up the parts of the covenant which your characters use, but seemed like a good idea at the time, I presume.
Basically I think the idea was to stop people just stashing personal Vis Source, which was the obvious buy in the previous edition, into their covenants as a free virtue, but I don't think the implementation is great, here.
I would only use it if the fact that you had a guaranteed personal income mattered in the saga. Like, if you were using 3rd Edition Rome, where everyone is broke and yet simultaneously there are a lot of Verditus around, or in the Alps, where your wealth is, in some cases, portable between covenants.
Most of the time it would be a Boon without benefit, and a Boon without benefit, like a Hook without stories, or a Flaw without consequence,s has a zero point value.
Well, they thought that it would be easy to get, but after a year or two they rewrote it a couple of times when they realized how little vis sources their covenant had. Now they have an annual incom of 9 vis (+1 vis for personal source for one magus). I did not want to sit as SG and say that their lofty aspirations of a vis stores to be that abundant.