My disclaimer: I don't know what I'm talking about BUT I think this makes since. Can someone who DOES know comment on the science here.
After reading numerous variations on decoction this is what I have concluded based solely on the science as I understand it.
Multiple decoctions are pointless. A single decoction adding the grain back for the second rest only after you reach your desired grain "cereal" consistency, breakdown, and color is all you need. After the first decoction rest and addition of all your removed grain, simply increase you mash tun temps as a stepped mash method to reach your desired resting temps.
As I understand the science, the resting temps are based solely on the reactions happening in the mash tun, bringing the cereal to boil multiple times does nothing any different than bringing it to boil once for a prolonged time. Breaking down the cellular structure of the grain is all you are really accomplishing, aside from altering flavor and color which can be accomplish in one boil as well.
This method would allow a much less labor intensive process for a multiple decoction recipe.
Anyone with knowledge here care to comment?