My apologies for the very long delay in reply (too many irons in the proverbial fire). And let me also qualify that I've not read through the discussion yet. But to directly answer your question...
A proper answer would require a proper definition of
consciousness which is, of course, problematic. But the feature of consciousness that I can point to which reinforces my thesis is that consciousness is unboundedly self reflective. Consciousness as we consider it for ourselves is
transcendent (in a non-metaphysical sense) in that a conscious entity is aware of its own consciousness.
A tiger may be aware of its prey. A tiger may also be aware of itself in relation to its prey (hungry, personal ability, relative size, stalking position etc) but, I would argue, a tiger falls short of consciousness, at the level I am imagining it, in that it is not conscious of its own process of cognition. It cannot ask the question "is it right that I hunt this prey?". The ethics question can only occur with a conscious entity because only a conscious entity can deal with the meta-question that comes with the realization that an ethic (value system applied to choices of behavior) per-supposes a meta-ethic (which ethic is better since the choice of ethics itself is a choice of behavior) because the conscious entity is self reflective.
It is like the fact that given a mirror one sees a copy of an image of the world, but given two mirrors facing each other one sees an infinite regress of recursive images of the world. The existence of consciousness in an entity allows it to explore that infinite regress as far as it chooses (though always to a finite degree of actualization). This is how we distinguish a computer from a conscious entity. Both can contemplate a starting condition, "one". Both can consider an act of iteration, "next". But only a conscious entity can appreciate the futility (sometimes) of the futility of forever chasing that "next' without realizing that the goal (which we symbolize as "infinity") cannot be reached. More to-the-point the conscious entity realizes that futility of this process ("infinity" is to the conscious entity a symbol taking the place of the absent boundary).
The conscious entity can escape the infinite loop trap because the conscious entity can reflect on the task of striving itself.
Okay, so with these reflections on the conscious entity, I argue that any objective model must necessarily fall short of describing the conscious entity because the conscious entity himself by (imperfect but adequate) definition must be able to transcend (again in this non-metaphysical meaning) the model. The conscious entity models itself in some limited by meaningful way.
Bringing to down to a more concrete level, I see a strong analog to the modeling of quantum mechanical systems (my expertise) and modeling conscious entities. To
observe a quantum system we realize that the act of observation is of such significance as to undermine the validity of other (complementary/non-compatible) observables. We lose the ability to describe the quantum system in terms of an objective state of all observable properties. Similarly with a conscious entity, to "measure" the state, to observe those variables which affect the conscious entity's behavior requires we interact in a meaningful way, specifically a way meaningful to that conscious entity and thus the entity is perturbed in a way invalidating other complementary/ non-compatible variables.
In a very specific example consider how a questionnaire on one's political "state" can, merely by virtue of rearranging the order in which questions are asked change the outcome of the answers. We can see this empirically via statistical analysis of cases. This means that the act of observing the conscious entity necessarily will affect that entity in ways that, for the very same reason it occurs for quantum systems, invalidates the objective description of said entity.
That's my immediate thoughts on the matter. I'm welcome to feedback to refine my opinion.