It’s a shame that after all those years the History in Rhino is still not being fixed and completely destroys the ORIGINAL INTENT of the user. Rather than following the user-set values and settings in the dialog box of “Blend surface”, History does its own weird thing and most of the time produces overly-complex and/or ugly shapes. We need, a smarter History update on “Blend surface”. I had countless of issues with History update similar to what @eobet posted above. 
Here is a simple example made with the latest Rhino 7 SR. Rhino’s History fails to update the blend surface, ignoring the blend factor set by the user.
Smarter history update on Blend surface.3dm (203.8 KB)
