I work it from the other end.

Last year, after a ~40,000 mileage run I had carefully planned to end the year with 100,003 miles. But I had forgotten that NA J class earned a 50% COS bonus instead of 25%, and ended up with 100,427 instead (the extra 25% on LAX-YYC-YVR.)

That's still better than ½%, but not quite the 0.003% "waste" I was looking for.