Scripting BlendSrf

No, but it will be available in the next Rhino WIP release.

Flow and Bend have been in RhinoCommon for a while.

Rhino.Geometry.Morphs.FlowSpaceMorph
Rhino.Geometry.Morphs.BendSpaceMorph

The functionality behind our SoftEditCrv and SoftEditSrf commands is not exposed in Rhino (yet).