It all comes down to fiddling with the settings. Trial and error.
If the aberration is causing the image to spread outside of the canvas, here’s a way to fix it…
Add a new layer underneath the original. Now navigate to Image > Canvas Size and set it like the image above (the amount you make it will vary depending on how big your canvas is. I usually go bigger than intended and crop down afterwards.), click OK and then set the base layer to white and then with the original selected center it within the canvas (make sure you have Snap toggled on under the View menu).
Now if you enable aberration you should be able to see it around the edges. :)