Top: made a curve with 4 control points, degree=3.
Bottom: made a curve with 3 control points, degree=3, then used “ContinueCurve” command to add a 4th control point, but the resulting shape is different and I know no command to make it again exactly like the top one, except than recreating a new one snapping on its points.

Is this expected?
It seems the knots of the “continued curve” follow a different logic than what it would have been if I simply continued the curved while I was originally creating it.

How can I “continue a nurbs curve” by adding new control points after one of its extremities , and have the resulting curve be the same as one that would have been directly created with the correct amount of points?

True, but the problem is still the same.
“Continuing” a curve will somehow keep old knot parameter and make a sort of “wrong” output curve.

Try it yourself.
Curve A = Degree 3 with 5 point
Curve B = Degree 3 with 4 points, but then add another point with “ContinueCurve” to have the same control points of A

Hello- MakeUniform would affect the entire curve, maybe fine in this case but potentially changing the shape a lot if the input curve is not uniform - better to do it yourself for now. RH-72579 ContinueCurve: makeUniform option