I am now an expert on batch sparging. I've done it twice.
First, the starch test can be inaccurate. It shows that there is no starch in the areas tested, but not that conversion is completed throughout the mash.
I simply leave the mash for 60 minutes. The excess time isn't wasted, because I use it preparing for the upcoming activities.
At the end of the mash, you end up with the mash at about 15? degrees (which is much lower than the temperature needed for sparging.
If you add 1 to 1.5g of near boiling water to the mash, and stir well, you will raise the temp of the mash to the required sparge temperature. Add the water slowly while stirring, and check the temp. You don't want to get over 170. When you get to 168, you can add some 168 degree sparge water, stir well, and let is sit for 10 - 15 minutes. The stirring exposes the sugars to the hot water, and the time gives the water a chance to dissolve the sugars.
After it is rested, you should recirculate until the wort is clear. This means that you draw of some running into a suitable container, and then return it to the mash (possibly re-heating the runnings if they have cooled considerably).
When your runnings are clear, you can discharge into the kettle as quickly as you want. With batch sparging, there is no need to discharge slowly.
When the discharge is nearly complete, and the grain bed starts to get compacted. you stop draining, add more sparge water, stir, rest, recirculate, and drain again until you have the desired volume, or until the gravity of the sparge gets down to 1.010 (below that gravity, you start to sparge out a lot of tannins).
IMHO, it is worth doing some experimentation with sparge water temperatures as the transfer mechanism from your heated sparge water to the MLT is never 100% efficient. You need to heat the sparge water to a temperature, that results in 168 degree water arriving in the MLT. In my case (while fly sparging), I heat the initial sparge water to 192 degrees, and add to a cooler, which I use as a HLT to drive a sparge arm. As the cooler isn't big enough for a complete sparge, I have to top it up during the sparge. This requires 185 degree water as not so much heat is lost warming up the cooler.
Hope this helps.