All my saves to date have been focused on Mina instead of Hana because I'm one of those people that always dates the same LI in every replay, so I can't point out the differences between routes buuuut tbh, I think Mina and Killian breaking up fits a introspective Killian perfectly, 'cause it's like a catalyst to get him to want to change his behavior
'course, you can still get that if you decide you don't wanna bone her but still make it a point to break them up
Also we haven't had the pay off of Ian finding out we are dating his ex yet, but I am also genuinely curious what's gonna happen, because a party boy Killian seems far more likely to just brush it off compared to a introspective one, even though you are generally a better friend to the introspective one, there's some interesting drama here.
Lastly, leaving Killian aside and going on my own little schizo rant...giving this is your first time going that route; you'll find that Mina & Edwin are more similar than it seems, both are so invested in a act that it has become their personality, to a point where they are disassociating from everything going on