Unexpected behavior PointAtNormalized for polylines

[pederlh]

Describe the bug
Starting with Hypar.Elements 2.0.0, polylines are parametrized 0 -> # vertices - 1, which changed the behavior of methods such as PointAt. In order to facilitate simple library updates, the convenience method PointAtNormalized using the old parametrization 0 -> 1 was introduced. However, even though this method deceptively appears to be linear, it is not. Should this behavior change or be clarified better?

To Reproduce
An sample polyline with three vertices is initialized below:

Polyline perimeter = new(new List<Vector3>()
{
    new Vector3(x: 0.0, y: 0.0),
    new Vector3(x: 8.0,  y: 0.0),
    new Vector3(x: 10.0, y: 0.0), 
}
);

Vector3 point0 = perimeter.PointAtNormalized(0.25);
Vector3 point1 = perimeter.PointAtNormalized(0.50);

Expected behavior
point0 is located at x=2.5 and point1 at x=5.0.

What happens
point0 is located at x=4.0 and point1 at x=8.0.

Bonus
Is there an elegant way of changing from old to new parametrization? The procedure seems to involve finding the length of each individual line + the total polyline length, and calculating the parametrization variable for each vertex.