Did your sheet take into consideration Cure II free procs and Cure III overpowers? Granted, those are on some unpredictable and unreliable mechanics, but they still improve HPM for both spells over a long fight.

Also, your HPM seems to only look at single target effect. A spell that gives multiple players healing benefit would not only increase HPM, but also reduces healing stress.

I guess the question is, what do we do with spreadsheet data for healing? Healing is completely situational and conditional. It's hard to utilize static figures for developing a healing strategy when any given fight will give you a different set of stresses and variable. Some fights, for example, may require more AOE healing.

Kudos on taking the time to figure this all out. I do not mean to discredit your efforts or trivialize their values at all.