my understanding too is that duals are infp-estj and infj-estp which seem much more accurate in my experiences. i think estp especially makes more sense for infj females, and the estp and estj males for females makes sense especially for 4s and 9s who are said to look for a parental figure (1s, 8s, and maybe? 6s) and often dig etj guys and etp men. infj 6s and 9s generally get along well with 3s bc they feel safe (that outward 3 confidence is oh so reassuring!).
5s also often like 2s, which is partly why 5 intps can go for esfjs or enfjs so easily. 4s and 4 wings often feel like 2 is going backwards or the wrong direction (disintegration). 6s and 5w6 are probably more appreciative of 2w3 than 5w4, who wants intensity.
i like enfp a lot. i like dominant intuitives a lot. but i am a 5w4 and i pretty much need to communicate profoundly continuously or i feel bottled up, so sharing perceptions and perceptual legibility/interpretation/anticipation are absolutely crucial for me. as a 5 i get 4s and i get 6s. 7 is like the 5 antidote. it pulls you out of your shell. 8 and 3 do not mesh easily with 5. we all think we're (OBVIOUSLY) right and communication is terrible as a result.
4w5 infjs have a very deep need for communication but they deal with their questions and concerns and inner life more in terms of ethics (practical reason), whereas 5w4 deals more in terms of knowledge/truth (the universal). as such they can hold out longer without communicating profoundly and meaningfully, as they see their individual journey as more of a behind-the-scenes backdrop for their lives (a quiet, PRIVATE project). whereas 5s need to chart-the-course more assertively or they feel wasted and incomplete and purposeless.
we used to talk about infp and infj as mirror images of each other. infj and enfp are more mirror images. n, f, t, s just facing in the opposite direction each moment. left-brained and right-brained version. infj and entp are like alter egos with the same judgment just flip-flopped in order of importance. and intj and infj share the exact same cartography on their journey.
infj males are less likely to go for a T woman, but in the end it does promote growth and self-sufficiency and rationality in a very positive way. tho at times the intense F saturation of an nf woman, too, is extremely refreshing, cleansing, and regenerative (for all things F- colors, music, art, delicate shades of feeling, selfhood, personal values (read: valuation), etc).
also, some people test way more partners before being able to accept anyone. some people accept others almost wholly right off the bat. some are far more dedicated/committed to ltr and others don't need it nearly as much, or value it at different points in their lives enough to make it worth its while. these somes make all the difference when you don't line up with another and don't see why.
enfps seem scattered to infjs bc their thru traffic is so much higher and the idea that they are so much more capable as extroverts asserting their wills in the world makes us feel like we are at a disadvantage. our insecurities and defenses are largely built out of these fears, which stem from our lack of practice and lack of formulae to consult when we need to make something happen. we seem them scattered so far across the soil and worry so much about the grammar of the situation as if it will protect us, and oftentimes we are inexperienced enough and do not have the efficacy/confidence to realize that someone could, in fact, want to stay with us at all, choose our travel package over that of our competitors. and we're just afraid of getting hurt, which happens easily when you haven't shed your relationship baby fat and disillusioned yourself (and your incomplete and inaccurate upbringing/heritage) in the fiery furnace of the world.