Idea to fix Chalice - Add a charge system to restore a % mana after xxxxx spells are cast

All current Chalice of Harmony effects and cost remain the same but add...

Chalice now stores a charge on each spell cast. Once 3 stacks are acquired the cost of the next spell is restored over 3 seconds OR some sort of % mana restoration over 3 seconds. Stacks cannot be acquired faster than 1 charge per 4 seconds.

Could something like this get mages back on the field in mid?

-Doesn't give combo spamming assassins the ability to spam more combos because of the delay between charges -Reinforces the mage role of doing consistent damage by helping them cast more spells but DOESN'T allow them to spam abilities on the cooldown. -Doesn't help tear stacking champs because its too slow

Thoughts?