Support for Ars Magica 2 would be an awesome feature, as it would let you makes spells require more than just the average cheap items to make.
Ars Magica is a cool and popular mod, but has very limited ability to have other mods/items integrated into it.
Support could include:
Spell Shapes
Spell Components
Spell Modifiers
Obelisk Purifying
Essence Refiner