It may seem a bit unorthodox, but I'd definitely use a simulator that could model healing and absorbs done given a set cast chain, under varying secondary stats. Especially if it could spit out a mana deficit for the entire chain after accounting for mana returns.
I know this kind of information can be calculated directly. IE, you don't really NEED an actual simulator to find stat weights for healing. However, it's rather bulky/restrictive trying to do it in a spreadsheet, and there's no way you'll be able to see what amounts of devation to expect because of crit.
Hard right now to estimate secondary stat values for healers. Requires lots of trickery and experimentation.