The Modeling Guide blending documentation is wrong.

[ktbolt]

The Modeling Guide blending documentation shows the following Modeling tool Blend panel

However, the Blend panel in the current SV GUI looks like

None of the parameters in the lower part of this panel are documented.

[ktbolt]

The radius parameter is used to define the radius of a sphere centered on the interface between two faces. All triangles within this radius are somehow used in the smoothing process.

I'm still not sure what the other six parameters are used for.