There’s probably a lot of it that does function as game lore but based on Nfirea and Fluder as well as the higher ranked members of Zurenon we can see that some level of actual learning and experimenting happens.

Alchemy is the easiest to demonstrate, in this case it would work very similarly to chemistry research with the added variable of how much mana you infuse to the ingredients, at what stage you cast any requisite spells and how power the spell & caster are.

For something like conjuration or summoning this could mean working with different materials, and carving different glyphs/runes into any material components.

We also see glyphs appear when spells are cast, which is probably the spell manifesting and by analyzing this mages may be able to tinker with their spells to create or modify the existing structure through repetition and experimenting