Okay, let's say that there is an explicit game design need for the "on use" effects to work as they currently are, and that mana-tracking affixes fulfill the role that I'm suggesting. I can see that for Rathpith Globe and Gluttony specifically, with a personal maybe on Shroud of the Lightless's Shade Form trigger. However:
- Why is Disintegrator worded "25% chance to gain a Siphoning Charge when you use a Skill" and not "25% chance to gain a Siphoning Charge when you Spend Mana on a Skill"?
- Why is Tawhoa, Forest's Strength worded "35% chance to gain an Endurance Charge when you use a Fire skill" and not "35% chance to gain an Endurance Charge when you Spend Mana on a Fire skill"?
- Why is Eber's Unification worded "Trigger Level 10 Void Gaze when you use a Skill" and not "Trigger Level 10 Void Gaze when you Spend Mana on a Skill"?
- Why is Zerphi's Last Breath worded "Grants Last Breath when you Use a Skill during Flask Effect, for (450-600)% of...