[DjScribbles]

The argument for the bias vs sensitivity does make sense; can the same pattern be applied to the bias instead of the sensitivity? (i.e. is there a Gyro::SetBias method)

Also, what was the final sensitivity value you reached with this calibration? Was it a realistic value?
If what you did cut down on the drift significantly when deg/s = 0, it seems as though it would have to push the sensitivity to an extreme value where any error in bias would not accumulate as any significant angular value (but the voltage error would still be present); and in this case, the reported angle would be very inaccurate when any rotation is applied.