Your list isn’t structured for nurbs surface creation as there are discontinuous depths as currently showing. Flatten is a no go - you need a L3 list to make these nodes work.
Instead of trying to add additional curves which aren’t in sequence/aligned with the existing sequence, try adding the missing points via a means something along these lines:
You’ll need to split your base ellipse to grab the end conditions (some nodes to consider: List.First, List.Last, Curve.Extrude, Polysurface, Geometry.Split, Curve.PointAtEqualSegmentLength, List.AddItemToFront, List.AddItemToEnd) here as needed, but this should get you started.
Alternatively you could take any of the dome surfaces above and split those by the perimeter curve for where you want to start and end your new surface (likely more accurate and less computationally complex than attempting a rebuild using nurbs by points).