As you mentioned, it is difficult to come up with a theurgy for the Hollow Ones and the Sons of Ether. This is simply because these tow Traditions are so individualistic in nature that a basic theurgy is different for each mage. In the end, theurgy for the Sons of Ether is personal and, in a way, fun. While Sons of Ether believe in science, they believe in a personal science, designed for the experimenter alone.
Science is supposed to be a matter of discovery, wonder and, in the end, fun.
When science is fun, it becomes a unique theurgy for a unique Tradition.