When I use a brew-in-bag approach for small batches (5 gallons) in a 6.5 gallon kettle, my digital thermometer readings vary by 10 degrees depending on where I place the thermometer in the wort. My process is typical. I place the bag in the kettle, bring the water to several degrees over my target mash temp, pour the grain in gradually and gently stir a few times - just enough to break up dense clusters at the bottom. I do not pick up the spoon again and I do not mix thoroughly on advice from others. I have no trouble with the mash temps dropping over time when taken on average at many points in the kettle. A typical mash for me might have areas that read 157 and others that read 148. The mash can get a bit dense with my heavier grain bills (14.5 lbs) but not more than runny oatmeal. Since the mash temp plays one of the biggest roles in the results it’d be nice to not have to average such widely varying numbers. Some would definitely freak out most people if the wort were all that warm. In general my results are good but could be critiqued as having too much for a style on occasion - possibly due to some parts of the wort building out extra long strand sugars that the yeast can’t ferment. It’s subtle and I don’t know this to be the cause but I’d like to know for sure what temp my wort is mashing at. Am I being too cautious about stirring or is a small crowded kettle inevitably less even in temp than a larger insulated mash tun?