In the woods, I'd rather file the chain than swap to a sharp one
because the saw is likely to leak bar oil badly if a chip gets caught
under the bar near the oil hole. There is a paintbrush in the toolbox
to clean around the gas and oil caps before refilling but it doesn't
work well if soaked with sticky bar oil. I am NOT about to clean a hot
saw with gasoline while standing in dry leaves next to my tractor.
Besides, touching up the chain gives the saw time to cool a little
before refueling.

At home I'll swap chains after blowing out the sprocket area with
compressed air.

jw