Hi Keith,
Not really, the 0.1mm tolerance is to allow for variations in the calibration of the calipers used to measure the diameter of the stone. It really means that the minimum size is 10.0mm but if the Judge measures the stone at 9.9mm then the stone won’t be disqualified. If you adopt the philosophy that the minimum size is really 9.9mm then you run the risk that the judge will measure the stone at less than 9.9mm and disqualify it.
Regards Gordon