For, now that they have basically functioning spectroscopes, they can start learning to modify spectra of light rather than just the way illusions look to the naked eye, modify electron orbital levels rather than just the colors that materials burn, and by doing exercises like those, hopefully, graduate to being able to modify the chemical properties and most-probable reaction pathways of materials via their understanding, and not just hammer from outside on their 'color', 'smell', or 'taste'.
The road ahead of them will not be easy! Not trivially easy, definitely! Possibly quite hard! They'll be performing magical manipulations that don't just do what they want right away, and instead push on weird invisible properties, properties that can only be measured indirectly, in spectroscopic properties or reaction rates. They'll have to hone their exercises of magical power until they actually do much of anything predictable at all; and then, by observing the little they can observe, often after the fact, they'll have to figure out how to affect complex systemic properties in a way that adds up to a functioning pathway of chemical transformations. There's math that can guide their way, but only partially, for understanding particular steps; they can't just calculate everything they need to do.
In short, it's going to be a lot like being a wizard apprentice all over again!
Only this time they will become MATTER WIZARDS.
And then use their MATTER WIZARDRY to produce ENORMOUS QUANTITIES OF ACID.
Then magically perfect the reaction pathways to refine spellsilver cheaply out of less expensive ore, drop spellsilver costs by a factor of 10, probably do some other stuff too, but also get started on making more intelligence headbands for new wizards who can make more intelligence headbands.
And now, begin!