[PAR_WIG1350]

If you raise the stick values to a power, instead of multiplying by a constant, you might be able to get more control at low speed without reducing the maximum speed. Typically, for this application, the value is squared or cubed.
Since all values are between -1 and 1, this actually reduces the value at all points. Just be careful about squaring negatives, you need to preserve the sign somehow.