Disable smart filters updating when image is cropped OR undoable distortion correction

I am having a problem that I can't find a solution to. 

Here are the relevant pieces: 

1. I have a wide-angle image of star trails, shot at 13mm so there is distortion.
2. I need to use a radial blur on the image.
3. In order for the radial blur to work as expected, I must:
4. Remove the wide-angle distortion using adaptive wide angle, so that the star trails become circular;
5. and align the center of rotation (just to the northeast of polaris) with the center of the document canvas.
6. However I then want to 're-distort' or undo the distortion correction on the final image. 

In order to be able to undo the distortion correction, it needs to be a smart object/filter. 

However when I adjust the cropping so that the image is centered on the canvas, the distortion correction updates based on the canvas, rather than the image. 

My questions:

1. Is it possible to have the distortion correction reference the image/layer rather than the entire document? This makes more rational sense, especially since it is pulling camera/lens metadata, but then updating for the whole canvas, which would never ever be valid...
2. If not, is it possible to disable the smart filter updating when the image is cropped?
3. If neither of those, is it possible to use another distortion correction that both sticks to the image AND is able to be reversed with ease?

I'm a photographer, not a photoshop expert, so I'm betting I'm missing something!