It may be basic, or to some considered a no-brainer-must-have. After all these years of using VCP and Shark, I had not stopped to inspect/explore the "Replace Curve" tool and feature. It is exactly what I am after for this current phase of modeling I'm doing.
What I have learned (think I have learned) is that in succession, each to-be-added curve follows the auto-select of the most-recently-added curve, until there are no more to be user-added.
SO, if between two surface-shaping curves you added 4 more, to redefine the surface's shape, you select the first curve, then go into the Feature Tree of the Concept Explorer. Right-click on the entity, then select "Add Curve". When prompted, select the curve, and do not click on the "Add As First" option. (If you skip around, expect the shape to fold back on itself. Not bad, if you're creating special surfaces or shapes.)
After you've added the new curve, Shark reforms the surface. After that, the Gripper still stays attached to the originally-selected curve (I guess to cue the user that the curve defines one of the edges, and the user selected it in order to access the "Add Curve" feature), if the user's eyes are quick, it can be seen that the recently-added curve is highlighted as well. In this case, it is good to have in advance turned on the control points so the line selections are more obvious when many colors are in play.
Do the same in succession until there are no more curves.
Next, I'll explore what happens when a solid is created from the surface, and other surfaces are projected as solids out to the original surface. (Hull sideshell, thickened, then "decks" projected out to the hull's inner suface. IN one experiment, days ago, I did not use the "Add Curve" feature and instead used the Gripper. It took, due to my model's size (~20-40 MB, depending on how much model is displayed at a save point, on disk, but around 700MB in RAM) maybe 20-30 minutes to fail. This time, I'll try curve replacement and curve addition.
