I'm happy you found it helpful!
One thing I think is important is that when you do venture outside of your comfort zone that it's something you genuinely want to do independent of if you find a dual who sticks around. Like my hike up the mountain was something I decided I wanted to do for myself because I felt it would be good for me.
This is good on a number of levels including 1) if it doesn't "work out" you still have had fun and 2) you become a more well-rounded person.
I think it's less that you become an identical and more that you visibly demonstrate your value for their values. Like you may not be "good" at doing the things they do naturally, but if you practice striving for the same goals you do gain some proficiency at least in bursts, and I think that's appealing to a dual.
For example, kindness is a huge deal for me in terms of people I like. I could be around the most efficient, comfort-making person and yet if they are unkind it's a huge turn off. (In fact, I might even sabotage them...) One of the big things that drew me to my LSE was his thoughtfulness and consideration toward everyone around him. He's not always "good" at it, and he even has said multiple times that he feels it's a weakness of his, that he has to consciously think about how his actions and words affect others' feelings, but he values people's well-being a lot and so he tries. And I can see that and it draws me to him.
As someone mentioned earlier, a lot of people have an idea in their minds of the type of person they want, and often it's a very similar version of themselves (only more perfect, lol). But it's not what's best, or even better. Once you're around someone who values the same things you do and yet has complementary strengths the ideal can shift a bit.