I think that the quality/development of one's functions can be divided into three categories and/or levels: Meta, Objective assumption, and Instinct-based.
People that often use their functions in a "meta"-way means that they excel at using their given function. Every cognitive function has a "meta" version of itself. For example, Ti has a meta-Ti which refers to applying one's personal logic to one's personal logicizing. ("My thinking is generally unbiased therefore..") Si has a meta-Si which refers to an awareness of what information one knows and also what other people know, as opposed to just accessing information. ("I know that I know how to tie a shoe. I also know that he knows how to tie a shoe.") The same logic can be applied to the other functions. Ni is creating ideas pertaining to one's ideas perhaps? Anyways, the key thing to note is that's it's all about an awareness of one's own mental processes. Perhaps the functions can also intersect with each other such as meta-Ti + Si. (I think I know this therefore..)
Conversely, people that often use their functions in an instinctive manner wherein they are not aware [they don't question] of how their instincts are driving them means that they are underdeveloped at the given function. For example, an instinctive-Fe is an Fe that judges people according to a social value norm without an awareness that they are judging the person based on a social value. [We see this a lot in society.] ("Ew, that is gross" or "That is not right.") There is not even an attempt to reflect on said judgment. Again, the same can be applied to the other functions.
The awareness of concepts relating to function maturity and immaturity can help in developing one's functions but do not necessarily translate into having these maturities as our minds work on their own in reminding itself of being more self-aware, in a meta-way, of its function usage.
Additionally, people that often use their functions with an "objective assumption" also means that they are underdeveloped at that given function. "Objective assumption" is when you think that the object you're detecting with the specific underdeveloped functions is objective. For example, ideas relating to "objective morality" or "objective aesthetics" is a form of underdeveloped feeling functions. Ideas relating to "Objective methods/solutions" is a form of underdeveloped thinking functions. "There is only one way to solve this problem." Again, the same can be applied to the other functions.
People that often use their functions in a "meta"-way means that they excel at using their given function. Every cognitive function has a "meta" version of itself. For example, Ti has a meta-Ti which refers to applying one's personal logic to one's personal logicizing. ("My thinking is generally unbiased therefore..") Si has a meta-Si which refers to an awareness of what information one knows and also what other people know, as opposed to just accessing information. ("I know that I know how to tie a shoe. I also know that he knows how to tie a shoe.") The same logic can be applied to the other functions. Ni is creating ideas pertaining to one's ideas perhaps? Anyways, the key thing to note is that's it's all about an awareness of one's own mental processes. Perhaps the functions can also intersect with each other such as meta-Ti + Si. (I think I know this therefore..)
Conversely, people that often use their functions in an instinctive manner wherein they are not aware [they don't question] of how their instincts are driving them means that they are underdeveloped at the given function. For example, an instinctive-Fe is an Fe that judges people according to a social value norm without an awareness that they are judging the person based on a social value. [We see this a lot in society.] ("Ew, that is gross" or "That is not right.") There is not even an attempt to reflect on said judgment. Again, the same can be applied to the other functions.
The awareness of concepts relating to function maturity and immaturity can help in developing one's functions but do not necessarily translate into having these maturities as our minds work on their own in reminding itself of being more self-aware, in a meta-way, of its function usage.
Additionally, people that often use their functions with an "objective assumption" also means that they are underdeveloped at that given function. "Objective assumption" is when you think that the object you're detecting with the specific underdeveloped functions is objective. For example, ideas relating to "objective morality" or "objective aesthetics" is a form of underdeveloped feeling functions. Ideas relating to "Objective methods/solutions" is a form of underdeveloped thinking functions. "There is only one way to solve this problem." Again, the same can be applied to the other functions.