As you know I personally favor the other position but for current purposes the main comment I would make is that whether we believe the theory or not, I presume you would agree that the long discussion of images in Lucretius book 4 and other places in the texts does confirm that the Epicureans did consider "images" to be a physical phenomena of atoms moving through space, and not a matter of simple "thought." Right(?).
And how do you view the Velleius material in "On the Nature of the Gods"?