Xiaomi switches have temperature sensors

Has anyone noticed and used the temperature sensors that are available in the Xiaomi switches. They show up in my devices:
WXKG02LM
WXKG03LM
WXKG11LM
MFKZQ01LM

I raise this because whilst they output a temperature reading which changes with the environment they seem rather a long way out. Eg one shows 25c when the room is around 18c. I am considering creating sensors from these which have a correction factor. Not difficult, just looking for any experience as to whether for example simple subtracting 7 will sort it?

Anyone else been there done that?