When I said some, I did perhaps undersell it. There were a lot of sidebars.
Sure, the master can imbue the virtue, if he has it. He cannot imbue a virtue he doesn't have. If these are Hermetic virtues, I should think that a master can imbue any virtue he pleases, if he has the ability, otherwise to do so. I'm teetering on an HR that allows the player(s) a choice in a hermetic virtue or flaw that comes about as a result of opening the Arts, match major for major minor for minor, it doesn't matter, could even be 1 major for 3 minors or 1 minor for 1 major (these are all comparing virtues to flaws, respectively). It's going to be a way to define the character and what path he'll follow through apprenticeship. It seems mystical. The Master (as a character) shouldn't know what he's going to get out of this process of Opening the Arts. It happens, he determines the results, and then he plans out how he's going to work with what he's got going forward. Seems mythical to me, that's just my opinion. And if someone wanted to randomize results, I'd be fine with that.
When HoH:S suggests that Jerbiton search for Gently gifted apprentices and are willing to take less intelligent magi as a result, that really strongly suggests that Gently Gifted is innate. It's not explicit, but to my reading it's darn close to saying Gentle Gift is innate.
Perhaps I liked the ambiguity, the wiggle room to let my imagination flow.
I would never have come up with some concepts I did, or quite simply they likely wouldn't exist in a "real" mythic europe.
Concepts such as Tektonius, my Rigid Magic Unstructured caster, which came about as a result of the discussion of Unstructured Caster Hermetic Flaw. He can't cast any spells he knows! The other is Talia, who had deficient Ignem and the master didn't knowingly inflict that flaw on her, and tried to fix it, or she had it innately and he tried to overcompensate for it. Those concepts become less plausible when viewed through the lens of Apprentices.