Honestly, I think Yuuki should realize that this arrangement isn't going work out with him catching feelings but her not ready to reciprocate and to move out.
But then there wouldn't be a manga so of course he wouldn't do that. And he would only make that kind of decision if he had more experience in the first place.
The thing is, he was supposed to have a girlfriend in college for what? half a year? Yeah, that's not a lot of time but he shouldn't be this inexperienced I feel like.
Also, while Yuuki is right in realizing that maybe he just put his expectations on her, I get Ban's friend chiding her because she should've realized that if you suggest practicing a relationship to someone, they're going to assume it's because you're both inexperienced.
And honestly, Ban was being kind of exploitive in suggesting this to practice actual "love" and not just simulating a relationship. It's not surprising that someone would start catching feelings in the previous case but Ban should've realized that someone is going to get hurt because in the latter case, someone will definitely have to catch feelings and to find out that she's just using that to work out being in love with the intention to then go on to be in an actual loving relationship with someone else is cruel. It's not going to be a mutually beneficial practice situation for someone like Yuuki. That's why I think that Yuuki should probably drop the whole thing but of course he's not and there's going to be all this drama before they end up together.