I would like to dynamically set image.prealign. This affects the geometry of the image object, so it would require an updateobject() call (ideally, it wouldn't, but I understand if it does). Unfortunately calling updateobject() after setting image.prealign does not seem to actually update the geometry to include the new image.prealign value.
I think that setting dynamically the image.prealign is not possible directly... It sets the prealign parameter with a new value but has no effect for the currently loaded pano (as changing the image.type or url)...
To make the changes, you have to reload the pano using the reloadpano() action...