Challenges with MeshWriteData

I am trying to use generateVisualContent delegate to create a procedural line mesh, and I am having some issues. So imagine a vertical line segment from A (bottom) to B(top). I want to draw a line from start to end with a width value. So say w = 5 * Vector2.right.

So my vertices for a given segment should be:
0: A.position + w
1: A.position - w
2: B.position - w
3: B.position - w
4: B.position + w
5. A.position + w

Right?

I set these vertices with the SetAllVertices method, followed by a...

Challenges with MeshWriteData