I'd get a new scale. I have
One that I bought on Amazon for $14.00, it measures in the hundredth of an ounce.
If you are being forced to 'round down', then you are making a mistake because your lye/water is based on the numbers you put in your
soap calculator. The first time I went to make my GMS, I rounded my weights to whole numbers, but I did it in SoapCalc, so my lye/water was based on those numbers. Of course, adding whole oil/butter numbers doesn't make my lye/water numbers come out whole and if I were to round those numbers, I'm changing my Lye Concentration and could potentially end up with a negative 'superfat' or have more lye than I need, or I could end up with MORE superfat than I want.