I think I've used Method Caster a handful of times. In those times, they didn't do anything except for the ritual spells which might have changed the fatigue lost from 1 to 2, but otherwise it had no impact on the story.
Can I swap this out for Adept Laboratory Student? The "cool" thing about doing this is that Talia will never have taken advantage of it heretofore, and I'd work it into something in a kind of accidental way. Adept Laboratory Student fits the underlying concept a bit better, and I can still sing the spells, it just provides no real benefit, as far as I had envisioned it for Talia.