Rebuilding Curves method suggested

Hi. I’m revisiting a file I created in Rhino and making changes.
I am using intersections of planes to find curves, and I would like to rebuild them as close as possible to the original curve. I am trying to achieve continuous surfaces.

It has been a long time since I created the file, and I wonder if Rhino 8 brings progress in reconstructing curves to achieve single-span surfaces. At one point, I found that Cademy. xyz had a technique via Grasshopper in which they used a node setup to recreate an Apple-style continuous radius that seems to work in approximating curves.

Thank you