Wow, that's a good question. I think I do want Star and Marco to end up together, even if that's going to take some work.
I think Marco is more in love with the idea of Jackie than the reality. He still feels really intimidated and unworthy of her interest in him. Once he gets over the fact that Jackie actually likes him back, she's not going to seem as special. And she's a nice girl who doesn't have as much of a stake in staying with Marco. I don't think she'd have a problem stepping aside for Star if it seemed they both wanted to be together.
And Marco really cares about Star. He's spent so much time helping her and looking out for her as a friend, it seems like they've got the better foundation for a relationship. Marco can see Star's flaws and cares about her anyway.
But obviously Marco isn't going to instantly dump Jackie just to make Star happy, and obviously Star didn't want to impose on Marco's interest in Jackie.
I want them to get there and I think they could, but it won't be easy.