This is one of the most useful 3D commands. In basic terms it takes a…
Vectorworks Tip 368 – Extrude Along Path (Relationship Between Path and Profile)
When you create an Extrude Along Path, the centre of the profile is always located on the path. This might be the reason why some of your extrude along path objects do not match the 3D model you wanted to create. But you can edit the location of the profile relative to the path after you have have used the Extrude Along Path command.