I have Displacement constantly cast on my melee bard. Yes, it does mitigate a lot of damage, but I'm still whipping Heal scrolls in EE. Consider also, said bard uses a Celestia in one hand (UMD check), so there is some slight UMD lag switching out to a heal scroll and back in.
I'm not saying you're wrong.... you're totally right... just there may be other things to consider.
As far as these cookies? Suck, suck, suck for the reasons given already. I gave up eating Abishais on my DC Cleric. 5 inventory slots, and by the time I've eaten them, my group is waaaay ahead of me.