Of the 6 I just ordered one is running noticeably hotter than the rest. I think I know what I'm doing next weekend.
Temperature difference between the 2 hashing PCB was reported to the engineers and it was reviewed. So far, it is not the hardware caused issues, but rather where and how the miners are being deployed and managed per the engineers.
The temperature sensors are also rather crude, and on a large scale there will be plenty of 'miscalibrated' ones. I'd be more suspicious of the sensor reading incorrectly than one board running significantly hotter.