Last expansion savages:
- Almagest
- Charbilis
- whitehole
- Timely heal and shield checks on god kefka heads, neo black holes, final omega patch
- Annoying single target heals on Dadaluma bleads, O6s tank autos, M&F double TBs

Probably forgetting some.

Current expansion:
- Timely heal and shield checks: Voidwalker double flare, shiva knockback mirrors
- Annoying single target heals on Voidwalker dps 1hp before puddle, furor conflag maybe?

And errr that's all I can think of and I'm already pushing it a bit. Week 1/2 shiva was pretty rough on heals, not because of any checks but because of how optimized you had to be to carry enough dps.