Lilies are really terrible and I feel the need to say it at every opportunity, even in the DPS forum. They get consumed in the course of using your best abilities, yet they're also required to cast the sole mitigating ability in the WHM arsenal. This is... unwieldy (to put it kindly). Compounding this is the restriction against getting a Lily from a 100% overheal. I have to intentionally not heal somebody to full in Savage content when I know that I'm going to need to use Benison. And if the other healer can't read my mind and tops them off, or if I'm "lucky" and get a crit, I'm SOL.

I'd say it's hard to imagine how the design could've been worse, but then it originally was worse.

This is the problem with having shield healers. Benison is a vital ability which is used constantly to partially absorb gigantic hits which are only so gigantic because they're tuned to eat through the regularly-applied shielding of SCH/AST. Thus putting restrictions on it is an inherent problem for WHM, but removing restrictions exacerbates the underlying problem. It's a feedback loop.