I mean I'll almost always use my buffs off CD since I do nothing but big pulls. But if I see the healer is one of those that likes to stand around just throwing heals with plenty of downtime I'll cut down on my tank CDs so they actually have to work like the rest of us.

I've seen far more lazy "I don't have to dps even though I'm currently doing next to nothing" healers than I've seen tanks who refuse to use CDs intelligently