I have no experience with that controller, but it's at least possible that it's adjustable. Pop the cover off- if you see these guys on the PCB, you can *probably* adjust the hysteresis:
As to whether or not it's recommended to fiddle with knobs under the hood of that thing... well. If you have a multimeter and a basic knowledge of circuits, you're probably ok fiddling. If not, I'd settle for the 3.5 degree setting.
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