Well, according to Huimin, those memories don't feel like it belongs to the current him. So, if he says so then it's true. And that's the thing about split personalities, no matter what happens to the same body, if the personality was changed during the times it happened, only the other personality would remember it and be traumatized.
Although, the body might react, the brain won't because it's another personality in control and they weren't the one who experienced it.
Tbh, I don't think that what they have is a product of Stockholm syndrome. Since in the first place, Huimin doesn't see Iheon as his captor or anything. As a matter of fact, Huimin isn't even in captive as he easily escaped Iheon.
From my understanding, Huimin is not being with Iheon because he is a captive that is forced to harbor positive feelings for his captor. At the very least, I don't see them that way.
"as long as you don't hurt me, I will forgive you", that phrase is totally valid for me because in this timeline, Iheon did infact not hurt Huimin. Unlike in the previous timeline, so yes I believe it's totally valid for Huimin to say that as way of saying, "Hey, you haven't hurt me yet. So, as long as you don't hurt me. I can forgive you".
But hey? All of us got our own opinion so ╮(￣▽￣)╭ Btw, your comment makes total sense so no need to worry about that
It definitely good but for me, I think it's hard to forget and experience/memories shape who we are. And abuse, rape, Stockholm syndrome etc. Is the biggest experience/memory that we will never forget and it will so much hard to forgive someone who did that to us. So for me, his action is none sense and the "as long as you don't hurt me, I will forgive you" like that is so stupid. (Idk if my comment make sense, sorry)