This is an issue I have encountered in CS6 & CC since I've been using a slightly different workflow on a few projects.
I create a smart object, say a coposite of a landscape with a road in it. I add a Radial Blur (zoom) to and move the origina point, file looks great and is adjustable as a smart filter.
Problem occures, if I use Radial Blur (zoom) on another image and change the settings and vanishing point. - When I return back to the image with the blur as a smart filter, the zoom origin point has reverted back to be centred.
If anyone has a workaround for this, please let me know.
On the subject of Radial Blur (zoom) a feature I would like is to be able to set the origin point of the zoom to be outside the canvas area.