If the ability regeneration triggered by the effect is supposed to be as low as it is then it should remain active for as long as an individual is being healed. As it stands the ability regeneration granted by Ember of Benevolence is not enough to warrant using it over other fragments. Even when building purely for healing, it had worse functionality than the other fragments that regenerate ability energy. Also despite it being stated that Ember of Benevolence should activate upon someone entering the a rift, it seems that it will only activate for someone once, and then never again including if a new player enters the rift.