Reading Thomas Metzinger -- vehicle vs. content

On page 294 (5.4, "From Mental to Phenomenal Self-Presentation:
Embodiment and Immediacy"), the author writes "There will be a level
of elementary bioregulation, arguably a level of molecular-level,
biochemical self- organization, at which it simply is forced—from a
conceptual third-person perspective— to maintain the distinction
between content and vehicle." and later writes "As soon as more
empirical data are available, it will be a task for philosophy to
demarcate a more fine-grained level of description on which it is
plausible to assume a full match between content and causal role, that
is, the identity of vehicle and content." This is very unclear to me.

(BTW: Later, the author writes about the brain being insensitive to itself,
but does not discuss headache.)

There is an intentional vehicle-content distinction, and a phenomenal
one. The intentional, i.e. referential, content is obvious, it is the
referents (the representanda). The phenomenal content is "the way
certain representational states feel from the first-person
perspective." In 8.2 "Preliminary Answers" answer to "What is the
“phenomenal content” of mental states, as opposed to their
representational or “intentional content?”", "It is a special form of
intentional content, namely, in satisfying the constraints developed
in chapters 3 and 6." It cannot be right, since the constraints can be
only satisfied by intentional vehicle, not content. Is it supposed to
mean, that "phenomenal content" is the semantical aspect of
(phenomenal) experience? That would be an interesting thesis: how
conscious processes "feel" is what they mean. Continuing the question,
"Are there examples of mentality exhibiting one without the other? Do
double dissociations exist?", Metzinger says:

"Double dissociations do not exist. There certainly is unconscious
intentional content. A lot of it. But in ecologically valid standard
situations there is no conscious state that is not a representational
state in some way (for a nonstandard situation, cf. the abstract
geometrical hallucinations [...] [which are] purely Phenomenal
content). [...] there is no example of phenomenal content that is not
also directed at some target object, property, or relation. Please
note that this does not mean that the experiential subject has to have
the slightest clue about what the intentional object of his or her
experiences actually is. In many cases, for example, in living through
diffuse feelings and emotions (like jealousy), the original
intentional object may be millions of years away. It may not exist
anymore. The original representandum may be something that was only
present in the world of our distant ancestors."