In our saga, we have an Incomprehensible Inventive Genius who is generating really useful and innovative Regio-probing spells that nobody else can learn (including some experiments towards a breakthrough that slightly break the normal limits). They would be valuable for us, and excellent for exchange. Although he's willing to share his notes, none of the other magi in our covenant have had time to study them and reproduce his ideas. So if an ungifted scribe could do that work, we would definitely have arranged for that to happen by now. (As far as I can tell, this approach is the only way to work around the Incomprehensible flaw.)
So for us, this is quite an important task, and I don't feel it should be too easy, so I voted No in the poll. I also feel that it would be hard for a non-mage to understand the ideas involved, though not quite impossible.
(The other obvious use case is "you find the notes of a dead mage, and need to recover their ideas", but that hasn't come up for us yet.)
I am less convinced that working off a Lab Total is the right way to describe this task. It produces odd results. For example, we are in the position where our incomprehensible genius should spend a season researching a Creo Corpus spell purely so my healer mage can study it and get a leg-up on understanding his code. I'm also not convinced that higher level spells should be harder to follow than lower-level ones.
If I were writing the rules from scratch (which is a really bad idea!), I would probably make it some kind of Int + Magic Theory roll, perhaps target 15 or 18, with a +3 bonus for having the Gift and another +3 for being a Hermetic Mage (in the sense that you have opened the arts). This would be a seasonal activity, and repeat efforts would get a bonus for each previous season, probably a +1. This would allow an ungifted scribe with Magic Theory to decipher the notes with a few years' work, which I think I like.
There would also be a hefty penalty if the mage was being deliberately obscure in their notations, or else a separate "crack the concealments" roll.
I also agree with Daelnoron's suggestion that Enigmatic Wisdom should be helpful for this task. Unfortunately, our covenant has only one member of Criamon. No prizes for guessing which one he is,..
(PS Given when I'm posting, Happy Christmas/celebration of Mithras/Saturnalia/whatever else you want to all on the forum.)