So - Sundered Eagle (pg. 123) has some quick-and-dirty rules for describing generic Folk magic. Personally, I don't find it particularly flavorful, but it does its job as a way of describing a number of folk traditions that the Hermetic Order can effectively ignore, as someone (probably Bonisagus) has already integrated these effect completely and utterly into Magic Theory. The flavor text strongly suggests that the individuals in question have no actual magical power, but instead are relying completely on scraps of magical lore and external magical power.
Which sounds a bit odd, to me - while knowledge can be represented as a virtue, the fact that Folk Magic is Supernatural suggests that something more is going on. Unless this is something like "you can't start with this skill unless you have the virtue, in the same way that an NPC needs a virtue to start with Penetration or Finesse or a magic item." But that kind of lore is normally just represented by an ability being labeled as Arcane, rather than Supernatural. So, as written, it looks to be a (very minor) power in and of itself. (Probably a spillover blessing from a farie godmother, or a coincidental 7th son of a 7th son, or the great-great-great grandchild of a half-demon, or a consequence from Warping, or whatever.)
But regardless - I got to thinking: assuming someone developed (Folk) Magic theory - how many additional integrations would it take to essentially get Folk magic up to being "Hermetic Magic, but with only a few TeFo's"? Some thoughts:
In reading through the blurb in Hedge Magic (pg. 16) - it looks like gaining a theoretical understanding of a magic system allows you add your Folk MT to your lab totals, etc....except that Folk magicians don't have labs. So, I'm guessing really the ONLY thing this does is allows for the development of additional insights. With this interpretation, it' really just the bare-bones framework for taking on additional capabilities.
Assuming this is true, how many additional Breakthroughs would it take to get a low-rent version of Hermetic magic? I'm thinking the following:
2a. AL + Philosophae into Ceremonial casting
2b. Props into Ceremonial Casting
2c. Formulaic Spells
2d. Enchanted Items
2f. Techniques and Forms (which look to be highly specialized Magic Lore, honestly.)
2g. New Guidelines (similar to the existing ones and within the same equivalent TeFo's, but stretched a bit)
2h. Ritual spells? (I figured Rituals are a consequence of your magic theory NOT quite covering everything.)
Depending on this new Order's relationship to the Hermetic order, sources of insight would be either extremely difficult, or extremely easy to get - ie, it would be as difficult as it was to get ahold of a book of Hermetic Magic Theory or a lab text. But I'm also wondering just what the level of difficulty would be - as all the Folk magic is already incorporated into Hermetic MT - which at least SOUNDS like part of the work has already been done. But I'm not sure.