Yep, as things stand, hoarding lilies is generally counter productive in most cases.

It was possible to alternate between feeding assize and then blowing oGCDs in the 4.0 lvl 70 dungeons to boost your overall DPS, but the pacing and tank damage in the current two dungeons is slow enough that it just doesn't work now. Nor has it ever really worked in 8 man stuff, there just isn't enough single target healing needed for it to be viable.