Sprite.Create() with outline tolerance?

I'm creating sprites at runtime from image data, and need a way to call Sprite.Create() with high Outline Tolerance, in order to get a tight, accurate mesh. By default, Sprites are created with low outline tolerance, resulting in inaccurate meshes like this--

The same image with high outline tolerance has a much tighter mesh

While the Unity Sprite Editor allows for the adjustment of a sprite's outline, there appears to be no runtime facility for this. Does anyone know of one?

Thank you!