I like them on the GCD.

But obviously I am in the minority on these forums.

That said, lilies should be stronger than the emergency GCD spells of WHM, and yes, this is still a problem.

As far as generation goes, I don't think the math is that simple. It really depends on the timings of things, since a capped lily is healing potency left on the table, and if you are forcing succors while capping your lilies during uptime, I think there is something wrong with you. If Ultimate truly has less than 60secs of action at a time, I may actually stop looking into running ultimate; that sounds less fun than savage.

Blowing everything during downtime will still happen, though. Please buff lily heals.