One question I have not seen addressed is ‘how fo I bump up temperature real fast?’
In a 5 gallon batch at, say, 140 F, adding 0.5 gallons of boiling water will raise the batch up to around 146. This could be enough, or yiu might not want to increase volume.
It is not harmful to mash low, and increase temperature over several tens of minutes. This is called a step mash, and some styles (like a hefeweitzen) do very well this way.
In an all in one, likely your best choice is to recirculate the wort from the bottom (where the heat is, and the temperature sensor) to the top, using a pump.
If you have a Brewzilla, be aware that you can tweak yhe calibration a bit so the sensor more vlosely matches the malt temperature. Mine is set to display -9 F lower, and the mash us always spot on. Then again, I also recirculate almost continuously.