You could add the command “Srf Blend” option, type “using additional curves”? Perhaps it could serve to generate a blend surface with the condition that cross one or more curves.
Some CAD programs have a similar tool which produces degree 6 surface (7 control points), unlike the default “Blend surface” in Rhino which only has 6 control points. The extra middle (4th) row of control points is used to align the shape of the blend surface through the internal guide curve.
“Loft” already can do that, except that it’s limited to G1 tangency at either end and can’t match to G2. Perhaps the dev team could upgrade the “Loft” tool in Rhino 9 to support G2.