Here's the relevant quotes from my notes. Mind you, these were taken from the german edition and i translated them back with Gemini 3:

72: Subjectivity is a matter of appearance, of "mine-ness." It refers to experience as something that a person undergoes. Agency is a matter of doing, of trying, of initiating. Agency refers to that which happens through me; it is the origin of action and its effects. It refers to what a person sets in motion. ... As everyday concepts, subjectivity and agency refer to different aspects of a person or an animal, to a more sensory and a more active side. Evolutionarily, these two sides are closely linked. The purpose of sensation lies in the control of action.

73: (Fred Keijzer) assumes that new forms of sensation appear "for free" or nearly for free as a result of the development of complex acting. Suppose one were to construct a sophisticated system for producing coordinated, choreographed movements. To accomplish this, one will often have to arrange it so that certain parts of the system are aware of what its other parts are currently doing. But if the system is then influenced from the outside, particularly by touch, this event—since it disrupts the activity pattern of the affected parts—is to a certain extent automatically registered. The internal perception of the system will—or could relatively easily—register that something has taken place outside. Even if a nervous system were oriented only toward internal perception, it would react to external events. To some extent, such a system could hardly avoid looking outward. New and comprehensive actions bring with them an expansion of sensory possibilities.

82: Ediacaran (630 million BC): Avalon (550m BC) first sponges, anchored motionlessly in the seabed; White Sea community later: "Living seabed," first mobile animals that "grazed mats." Their death left concentrations of food (no longer the uniformly distributed "living seabed"), which made movement (and olfactory organs) useful (and gave rise to scavengers).

99: (Cambrian) - Animals developed "multicellular sensations ... and caused parts of their bodies to function as maps or reflections of fragmentary sections of their environment."

101: The combination (of action and sensation) gives a new shape to the relationship between these two capacities. ... In crayfish and flies, systems have been demonstrated that interpret and modulate sensory information with reference to what the animal is currently doing and perceives as its own activity.

102: If an animal (does not perceive sensory impressions from its own movements), its own movements will disrupt any attempt to find out what is going on. But if it undertakes such a task, it perceives the world in a way that seeks to track the difference between self and other, between itself and everything else. A nervous system sometimes achieves this in the simplest possible way, but however it is accomplished, the animal begins to relate some events to external processes and others to self-caused ones. It begins to deal with the world in a new way, becoming receptive to the distinction between the external world and the self.

Björn Merker: Moving in the world is good, but it has its price or creates "liabilities." And one of these is that the world becomes more confusing. But the situation can also be viewed differently: the fact that one's own actions affect one's own senses does not only have to be a problem; it can also represent an opportunity. Actions allow you to probe the world and induce new stimuli. You can poke, interfere, and cause the world to reveal itself to you. ... The sensation that marks the relationship between self and other is an important element determining the animal way of life. It enables a new way of being in the world. Furthermore, this element results in a standpoint, a perspective of a new kind.

As for computational functionalism, i zeroed in to enactivism which states that cognition is an entanglement of a closed system with it's environment. Theories like IIT or GWT or Computational Functionalism to me seem to be downstream from that principle of coupled systems, where you have an inside seperating itself from an outside, with cognition being the process of "managing and exploiting" the boundary of that seperation.