Does anyone know if the Courageous Primal Diamond (legendary meta gem) buff is consumed by mana free spells such as eternal flame? The mana balance may even out if it does due to our spells that do cost mana being the most expansive in the game, but it would make the gem seem less appealing. With a combination of Blizzard's brand new mechanic of fun randomness that is RPPM and it procing off of free spells, it may very well be not worth using.
EDIT: I suppose a power aura could track the buff to help ensure the buff is used for spells costing mana only, but most of the time an eternal flame or LoD would be used directly after a cast, seeing as they're instant.