Socionics is information metabolism...
strong functions imply a large metabolism of information related to that function
weak functions imply a large metabolism of information related to that function
Large metabolism being defined as a large consumption of information over time
valued functions imply a valuing of information.
--------------------------------------------------------------------------------------
Fi as a function is information related to subjective feelings, feelings not thoughts, so an awareness of one's emotional state "I feel sad, happy, etc". Also its critical to compare the difference between a logical observation of a feeling and a literal feeling... "saying I'm sad"... is not a cognition of a feeling.... feeling sad is a cognition of a feeling.
Fi differs from Fe in its subjective nature.... Fi is "this is my emotional state, it belongs to me".... Fe is "this is the emotional state created by this object". Loosely defined "I feel happy when I play with this ball" -- Fi. "The ball is fun to play with" -- Fe. One is a perception of one's inner emotional state (subjective). One is a perception of the emotional state created by the object (objective).
So Fi is a feeling experience from within oneself, irrespective of external objects. Fi as information pertains to the awareness of this inner emotional state irrespective of objects and directly experienced as "feelings" and not as thoughts about feelings (which is the thinking function acting upon a feeling function, information exchange between two functions).
--------------------------------------------------------------------------------------
Fi-ego is more accutely attuned to this "inner emotional state"... Fi and values this information as highly important.
Fi-PoLR is less accutely attuned to this information and de-value it, while aware of it, they tend to ignore it as pertinent instead preferred to forgo this information in preference of their ego functions.
Fi-PoLR is more than aware of their "inner emotional states", but its not "trusted" in a sense -- it escapes the focus of the ego and it escapes any kind of value for its importance. Fi-PoLR usually value Fe information. Their is insecurity in awareness of one's inner emotional state as opposed to awareness of the emotions created by something "object".
Fi-egos do not have this insecurity, they are constantly appraising their inner emotional state and constantly valuing the information they find. How they feel inside irrespective of the objective world outside themselves is always in their focus.
Fi-PoLR tend to constantly reject this information at first glance, not trusting it because it creates cognitive dissonance in the utilization of their ego functions. Usually they must work through the function indirectly by using their strong functions (Se/Ne and Ti). Fi-PoLR having Pe base functions tend to be more exploratory in nature, but seek these explorations based of of logical understandings of systems. Through their explorations they extrapolate super-id functions (Fe and Ni/Si), in a sense these explorations serve to achieve these inner states (dual seeking and hidden agenda). These inner states relate to (Fi and Ne/Se) but indirectly... an Fi-PoLR prefers the emotional focus of Fe, and extrapolates this information indirectly from the connection of their ego to their super-id.
Sorry for spelling/grammar errors lol....
Anyways consider an ILE, they explore the potentials and possibilities of logical systems with a hidden agenda of achieving a relaxed and Fe-receptive state (SEI), while the (SEI) achieves this relaxed and Fe-receptive physical state in order to understand the potentials and possibilities of logical systems. The idea is "I'm really good at this, so I'm using this to get something I need". The ILE uses their ego to get at some SEI-ego state and the SEI uses their ego to get at some ILE-ego state.
The unvalued functions are the opposites of these ego and super-id functions... If you value Je then its Ji, If you value Ji then its Je... valuing can be looked at as a preference in what information you take objectively and what information you take subjectively. This switch in preference is only devistating in your weak functions, because it leads to great effort with the ego to understand this information.... with ego functions, you simply consider the flipside... what Ne says about Ni, or what Ti says about Te... its rather immediate. But with weak/unvalued functions you must first utilize Ne/Ti to arrive at some Si/Fe and then consider what this says about Se/Fi.... usually that process takes a long time and seems very distant from direct cognition or experience, having a dual present helps expedite the process in a chain of communication. ESI's and SEI's can understand each other, but prefer different outlooks, ILE's can then be helped to understand the ESI's easier through their dual translating this, otherwise the pressure placed on ILE's by ESI's remains stressful and trying to understand the other is like forced psychological self-development or labor, ultimately leading to distance and recovery for mental sanity to be preserved.