It seems clear that Cosmic Consciousness become the Stream of Consciousness is the somewhat occult starting point for Whitehead's analysis. This is taken to be the flow of phenomenal time, and existential moments thereof become the noumenal actual entities of nature. These subjective observational elements become, in their active stage, the substances described by state vectors in Hilbert spaces, which descriptions may be understood as anticipatory prehensions. In their completed stage, the observational elements become the potentials for actual events in the mental poles of future actual entities. Such actual events give rise to event-particles, which are the presence of the past actual entities in the present actual entity, according to the principle of solidarity. So, contra Whitehead's own analysis, the conclusion must be that the subject-superject or concrescence is, objectively speaking, an event-particle. An event-particle is thoughtlike - it is a kind of singularity in both Hilbert space and real space-time. The arena for event-particles is thus consciousness itself, as the great receptacle of Plato. The point-instant is a finer-grained noumenal element of the underlying space-time itself.
In von Neumann's terms, the Cosmic Consciousness become Stream of Consciousness is III. The actual entity become subject-superject and concrescence, as well as the event-particle, comprise II. The point-instant is I. Within the development of the concrescence, the subject is III, the superject is II, and the object or actual world of the concrescence is I. So, the whole theory is a universal theory of quantum gravity, of the noumenal nature of space-time itself, as observed or mediated by the phenomenal elements of time and space. It is all about space and time, ala Einstein, fully integrated with subject and object, ala Bohr. These are the essential categories of physis, or natural science.
So, the upshot is that Whitehead's theory, especially as reformulated by me, IS the new quantum theory of the measuring device prophesied by Bohr after 1935. The theory of the duration and the enduring object simply has to do with the ontological foundations of the Schwinger-Tomonaga theory of the spacelike surface required for state reduction. Every probability function must be seen in the context of such a duration and enduring object that will interpret that probability function. The duration and enduring object constitute a von Neumann II, while the probability function itself is in the place of a von Neumann I. The von Neumann III in this context is the embodied observer as described by Kant's theory of the psychic faculties, sensibility and understanding. As amplified by the Kabbalistic theory of wisdom, understanding, and knowledge, this becomes a theory of knowledge, as a noumenal element influencing the structure of reality. People have misunderstood the character of the knowledge in quantum theory - it is of course not just epistemological or phenomenal, but ontological and noumenal. Bohr hedged on this simply because it is not part of the present quantum theory, but only the future quantum theory as established in essence by Whitehead.