Hi cyclistIII, welcome to the Personal Inventory board!
That's a really interesting insight you've had here, about someone "coming back for you", making the connection between that and your experience of your father leaving (which I agree would have a big impact on a child too young to process or understand).
I had a brief relationship with a uBPD last year, and similar to you, I don't want to be with him. For me, it wasn't about wanting someone to come back for me, but once I was devalued, to convince him I really was a good person, and we were good for each other, and to do what I needed to do to "bring the nice guy back"... .
My father was critical and angry when I was young, and unpredictable not in the sense that many people describe a parent ("when he came home I never knew which version of him I was going to get", no, it was more like he was "normal" a lot of the time but when he did react, it was sudden and very loud. So it's entirely possible that in wanting uBPD ex to be kind to me again, I was trying to "bring nice dad back".
It's almost like there's some secret part of me that believes if someone abandons and then "comes back" for me, that broken part from my childhood will be healed -- that narrative somehow feels more powerful than the healthier one in which someone just loves me and stays and doesn't abandon me in the first place.
This is interesting... .have you pinpointed exactly why this fantasy "hits the spot" for you emotionally? I know, you explained about your dad, what I mean is... .what would you feel if someone who'd abandoned you "came back"? What would you believe about yourself if this happened?
Understanding the emotional details of why someone "coming back" seems like it would be so satisfying, may help you be less vulnerable to being "swept off your feet" as you put it.