I don’t know how I missed this command until now. It is very useful! I wanted something like the essential proportional editing in Blender, but for NURBS CVs in Rhino. This helps!
Unfortunately, the UI for SoftEditSrf has some serious problems. First, as others have mentioned, is the lack of undo inside the command. Second, which is quite annoying and time-wasting, is that you have to leave the command and run it again in order to change the direction constraint for further adjustments. Another thing is that it snaps to a location other than where your cursor is, so if you want to zero out your adjustment before moving, you then have to look where it snapped to, move your cursor there, and start the movement again.
Having a soft move tool for NURBS CVs is absolutely essential, it seems to me. And it should work on dense meshes too. If it would only work more like Blender’s proportional edit feature, it would be amazing. It would be wonderful to be able to see a circle showing the distance and to be able to adjust that distance with the mouse wheel.
It would also be really nice to be able to constrain to move U and V at the same time, but not N, if that’s possible. And it would be great to be able to use the gumball and its settings to align to object, world, cplane, and view.
Often I see people talk about how denser surfaces are impossible to adjust. With a proper soft edit tool, that shouldn’t be the case, should it? I edit very dense meshes in Blender this way with no problem. Obviously, your surfaces should be as light as possible. But sometimes they need to be a little denser in order to properly match to other surfaces or to describe the shape you want.