NAF – New artifacts with unique properties.

As an option, in the Archmage tome, grant spells from all schools, but only of the 4th and 5th circles. Or, conversely, grant spells from the first three circles of each school and their mass or wave-enhanced Arcane analogs.

Definitely not 4 and 5, as these are all advanced technologies in one key, but 1-3 is fine. Regarding mass spells, I'm not sure (also a kind of advanced technology), but enhanced spells are definitely bad to give because it violates the racial uniqueness of Warlocks.