It is possible with FlowAlongSrf if you set up the “from” and “to” surfaces carefully - very carefully.
In the example below, I created both the flat and ellipsoid surfaces wiht the same procedure - RailRevolve. In the case of the flat surface it’s just a revolved line, for the ellipoid it’s a revolved ellipse quadrant. Same rail in both cases, an ellipse. That way the structures of the two surfaces correspond, and they have the same seam.
Then use FlowAlongSrf, base surface is the flat surface, target is the ellipsoid surface. Make sure you set AutoAdjust to No - otherwise Rhino will try to guess how the two surfaces correspond and will get it wrong 99% of the time. Then click on areas of the base and target surface that correspond.
FlowPts_Ellipsoid.3dm (406.7 KB)