When I've done Hochkurz, I don't recall adding 4 gallons to reach the next step! That would totally screw with the mash pH, as well as give an inadequate time to the lower temperature saccrification rest!
The first rest (maltose rest) should be held at or around 63C (145F) and its length is used to control the fermentability of the wort. A good starting point for its duration is 30 min. Longer for more fermentable wort and shorter for less fermentable wort. If even higher fermentability is desired an intermediate rest at 65C (150F) can be added. Due to its large volume the mash temperature should not drop much during that rest but you may wrap the pot into blankets to stabilize the mash temp even more.
The dextrinization rest at 70-72C (158-172F) needs to be held until the mash is iodine negative but may be extended to 45-60 min. Many authors contribute head retention and mouthfeel benefits to extending this rest. Finally the mash may be raised to mash out temp and subsequently lautered.
I'm only familiar with the Hochkurz schedule on a theoretical level, so my interpretation of what you're saying is that he should have mashed in thinner and added a smaller quantity of boiling water to reach the dextrinization rest - is that correct?
So I calculated all of my strike temps for my various rests but I have read some different techniques on how to batch sparge. On byo.com I read that people like to take the first runnings then add the next amount of water, restir, and then drain it off. But John Palmer seems to think you should add it all in at one time and then take a single run at the end. Doesn't running the water off affect the strike temps because there is less water? What do you guys suggest? Thanks.
First, I suggest you make sure you really need a step mash. a lot of the time it's unnecessary. Then I suggest you read www.dennybrew.com for proper batch sparging technique.