At first, thank you for writing this tool!
Now for my suggestion: I suggest to provide not one but two temperature-fan settings:
one for Increasing fan level and one for decreasing fan level:
Example: the fan swithes from level 0 to 1 at 46 degree. Now it would be nice that the fan stops only if the temperature gets lower than, lets' say, 43 degree.
Is that a lot of work?