How did you ramp up so quickly between steps?
I mashed in a 11 gallon kettle with a false bottom. Cranked the heat up (and there were a few minutes between steps). Vorlaufed until the runnings were clear. Ran it into a couple of sanitary buckets through a hose, so as to not oxygenate the wort. Cleaned the kettle out and removed the false bottom. Then poured the wort back into the kettle and started the boil.
Yes, I know that's not the "right" way, but it worked. (I normally do brew-in-a-bag, but that doesn't work well for a step mash)