Well you can already tell that if ichika confesses to him he is gonna reject her so if she ends up confessing next chapter that will be when that ship dies, but tbh she totally deserves it
Now things are getting interesting. What did the grampa say was the key to telling the quints apart? Love. Uesugi knew that Ichika imitating Miku wasn't Miku. Does this mean we have a winner? Or not because it doesn't appear that he knew it was Ichika doing the impersonation