To me, that immediately precludes 1, 2, and 3. Not because they don't look like the kisser or whatever, but because their character arcs, as of chapter 91, are effectively over. They've come to terms with themselves, their motivations and goals. Them winning wouldn't incite any more drama in the story, beyond that quint being very happy.
In other words, each character starts believing a "lie" about themselves and about the world they inhabit. Ichika believes that she can win through deceit, she's moved past that. Nino wants to get rid of Fuutarou, she's moved past that. Miku thinks she's not good enough for Fuutarou, she's moved past that too. These characters have all concluded their arcs, and though they could certainly have a new one, one that coincides with Fuutarou finding his bride - the truth is that if the manga is truly within its last 30-50 chapters, then this is the third act and character motivations have been established by this point. It's too late for them to really grow beyond who they are now.
Yotsuba has a firmly established internal conflict now, one with no simple resolution and would almost certainly require Fuutarou's intervention. It's not too hard to envision a scenario where Fuutarou decides he loves her, but Yotsuba refuses to accept it, creating dramatic tension and leading to a sort of reverse-chase that makes up the final arc of the manga. It's also not too hard to see an arc where Yotsuba gets her stuff resolved independently. If we see the latter in, say, the next 10 to 15 chapters, almost no way 428 wins.
Itsuki, in terms of story presence, is complicated, because she's been built to be something of an audience surrogate. Her role is mostly to be a bystander that watches the conflicts play out, but its certainly possible for her to be the winner, if she has an arc that coincides with the story's conclusion. But, this late in the story, it would have to start almost immediately.
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