I’ve added an example problem to clarify my issue.
In “Example.3dm” you can see the surfaces I’m trying to blend. Before I do this, however, I’d like to adjust the surface edge of the bottom surface. My best guess on how to do this would be to use the BlendCrv tool on the surface edge twice with tangency enabled (see images). After using BlendCrv I then have to project the blend onto the surface to create the new edge that I will be blending from. I was wondering if there was a tool in Rhino which would let me make these two steps simultaneously. So maybe a BlendCrvAlongSrf, or maybe another tool which would let you reshape the surface edge or surface edge curve along the surface.
EDIT: Maybe a project on surface preview option could be very interesting for the BlendCrv tool?
Example.3dm (88.9 KB)