No it doesn't. Converting metric to imperial WITHOUT understanding how ounces are counted does not create a false reading.
1kg = 1000g = 2.205 lbs = 2lbs 3.27oz
All of these are the same mass (with rounding at the lower decimal places), just using different notation... Your assertion is baloney.
Yes, the lower the weight, the less difference there is. BUT, I have 2 bats at home. One weighs 1162 grams and the other weighs 1148 grams. Once converted it looks like this:
1.162kg =1162g = 2.56 lbs = 2lb 8.99oz's
1.148kg = 1148r = 2.53 lbs = 2lb 8.49oz's
So you see, the difference is quite large when you up the weights of the bats. They are the same mass yes, but if you sell a bat and say it is 2.56 as that's what your scales have said, but when the other person gets it and they weigh it with the proper conversion, and it actually comes close to 2.9, then that's where it can be a problem.
I do like Baloney though