If Flash's blind effect is in full duration, it's actually semi decent to use clemency as a mini aoe threat move, in place of eclipse, if your low on TP or needing to get TP back, but dont want to use another flash. so technically clemency is more effecive at threat/healing, unless they have the TP to use single target instead, which they should single target.
The exception being the healer doesnt mind DPSing while u try to solo heal yourself for 3 GCDs.