You know, I really considered your question a while back. I did type myself as ESI-Se for quite a while. If I put just some points of why I reevaluated, it will not build a case for me. If I put all, it will make for a tremendous long block of text. I'll try hit the middle maybe. I have three younger sisters, who are all extroverted judgers, and they are all really attention grabbing, and me being the oldest one on top, I've pulled myself more in the background, more so for having ADHD and always getting in trouble if I tried for attention. So when I originally typed, I typed as ISFP. Obviously, that was just the first test, not knowing anything about functions or how their dynamics changes when set in different order. After a while, and talking to a bunch of people who were ahead in the whole MBTI business, I conceded that I might be ESFP. After a couple months, I thought if I really was extroverted, people wouldn't drain me so much, so I went back to ISFP. I am part of a Gamma group, and rather active in plenty forums, so I get to talk to a whole bunch of ISFPs, as well as ESFPs. It turns out that I am more out there, more active, more impulsive, more of a doer than any other online or real life ISFP I know. I also use my Te with more regularity and though in the long run it is stressful, if I do it here and there, it can be really fun and rewarding. On the other hand, I struggle with Ni, and it's something I tend to look for in others. My Se and Fi are almost level, but my Te is better than Ni. Apart from that, my instinctual stacking would explain some of why I have more personal than group focus, as I am sx/sp, and so in me is weaker than is average.
To answer you regarding the Dual theory, I like it, and it seems to me to be relevant. It also added a bit to my retyping. I know a lot of ENTJ women (meaning 4), and am friends with them. However, my dynamic with them is that we have a lot of fun together, we always get a lot of shit done when we spend time together, we motivate each other, but in the long run, if we spend too much time together, it gets really exhausting, and we tend to have fights, so we have to tone down the regularity for a while. While with INTJs, we tend to have this often unspoken level of understanding, and we have the opposite dynamics, that the more time we spend together, the more time we want to spend together. I admire their use of Ni, and when they know me enough, they are good with filling the void, and sharing a vision for me down which I would be enthusiastic to explore, and on the other hand, they get enthusiastic about doing whatever I come up with, whether it's just a big of fun, or whether I nudge them towards executing their plans. Looking at that, the ENTJ relationships I have seem to mirror that of Activation, while INTJ seem to mirror Duality for me. I took that as another evidence, that I might be ESFP. It doesn't stand alone, but when you add it to a myriad of other things I have considered, it adds validity.
Yeah, I'm definitely more of a risk taker than any of my ISFP friends, though, having a 6 in my tritype, it seems to be oscillating between hesitation and recklessness. I am both. I love the concept of coffee, because of the option to bolt

My relationship ended because of logistics and the situation mostly. Neither of us wanted to end it at that point, but there wasn't an opportunity to move it forward. We had conflicting scheduling, so however much we wanted, it was tough to see each other, and there were certain external complications I won't get in here. In the end it took us much longer to end it, and we have stayed friends since. Now I know him for 4 years.
Duality neither tires me out, nor do I get bored because the lack of action. It's like we create this bubble only me and the Dual are a part of, and it's exciting.