Disagree.
Agree. I've found several sources that make different correlations to INFP, but I definitely relate more to melancholic than phlegmatic.
Melancholic - A person who is a thoughtful ponderer has a melancholic disposition. Often very considerate, melancholics can be highly creative in activities such as poetry and art - and can become occupied with the tragedy and cruelty in the world. A melancholic is also often a perfectionist. They are often self-reliant and independent.
Affection Strengths In The Melancholy: Very faithful, loyal friends and self-sacrificing. Their feelings run deep and tender (even though they lack the ability to express these feelings). They easily empathize with others and have the ability to make very deep commitments.
Affection Weaknesses In The Melancholy: They are critical of others, angry, cruel, vengeful, emotional, rarely tell people how they feel, have a low self-image and are sensitive to rejection from deep relationships. The loss of a deep relationship (even by death) is devastating to them. (Sounds more relative to Type 4)
Phlegmatic - Phlegmatics tend to be self-content and kind. They can be very accepting and affectionate. They may be very receptive and shy and often prefer stability to uncertainty and change. They are very consistent, relaxed, rational, curious, and observant, making them good administrators and diplomats.
Because of their tendency to uninvolvement, they are natural negotiators and diplomats. “Peace at all costs†is their motto. The Phlegmatic has no fear of rejection and can handle unaffectionate and hostile people. They are calm, easygoing people who are not plagued with the emotional outbursts, exaggerated feelings, anger, bitterness or unforgiveness as are other temperaments. They are observers who do not get involved nor expend much energy.
Affection Weaknesses of The Phlegmatic: Unwillingness to become involved in deep relationships, tendency to be an observer only, rarely self-sacrificing, unemotional and inexpressive. Verbal defenses are used to protect low energy supply with regard to physical and sexual involvement. (Sounds more e9 than e4)