Change the degree of a blend curve, or change the parameterization of the underlying curve.
Change the degree of the picked blend curves
  sub-menu.
                  Change the parameterization of the picked blend curves
  sub-menu.
               I want all new blend curves to have a certain degree or parameterization?
Choose BlendCrv Tools > Blend Curve Create  
  ❒ and set the degree and parameterization options.