So the data comes from research sponsored by the company that makes temperature sensors. My thoughts are that this is not much more than a thinly veiled advertisement for Med Angel temperature sensors.
Like many others, I have been keeping insulin in a domestic fridge since becoming diabetic and have not had any problems with efficacy so far.
Temperatures inside a fridge will fluctuate. When the door is opened it will let warmer air in so the fridge has to cool down again but the point is that just because some of the air has become warmer, the items inside the fridge will not warm up at the same rate and are probably staying within range.
I have a cheap thermometer to keep an eye on the temp range - I don't need an app and a $50 sensor.