By definition (as would also apply to a car) commuting miles are those daily (or other schedule) rides between home and work (or school). I'd also count the miles on detours if you do errands along the way.
But the other utility miles, where you replace a car aren't commuting miles. Call them utility miles or whatever you wish, but they don't fit the definition of commuting, any more than the miles you'd drive a car after you got home would.
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