I guess since I've read a lot of comments on this episode, I'd like to provide my own take on the whole best girl situation. Possibly only a few chapters ago I wasn't really considering Manbagi as anything more than a wrench in the plot to stir up drama, but a lot of discussion here has made me think about both Komi's and Manbagi's impact on Tadano and to the story.
Komi is undeniably more prominent than Manbagi, having been around for a whole extra (in-comic) year than her. That being said, most of Komi's luster is strictly through the situations. (A lot of which I can absolutely agree are pure ship bait.) Although she would eventually lead Tadano into his first outing into his own emotions (White Day arc), she herself has had little to no character development (when they mentioned she was exactly the same starting as a second-year, I was frankly a bit crushed.) She's won little battles in her path to achieving comfortable communication, but overall she hasn't seen any major character developments besides her eventual explicit admittance to her affection for Tadano.
TL;DR Komi is all history and still a mystery.
On the other hand, Manbagi is a much newer character, and you can really tell it through her fairly consistent inclusion in the group's activities, almost as if she's been accepted into the "squad" (in the first year of high school, this included Komi, Tadano, and Najimi.) Almost immediately she began to have feelings for him, only truly accepting them after the festival. Despite this, many of her interactions with Tadano are very much tsundere in kind, even if not explicitly. Although Tadano has been especially dense with her affection for him, she acts in a way toward him that would make it seem she thinks he's "getting any ideas", hence why most anything about him makes her flustered. Despite her extremely barebones interactions with him, the moments where she thinks to herself or discusses privately amongst friends (think of Chapter 206 "Love") are full of insight into her character and give her not only depth but the readers' sympathy ("I just want... to win..." absolutely crushed me, even as a Komi x Tadano person at the time), which, if this side of her eventually were to be exposed to Tadano (as it seems to be the case here), I would legitimately think of her as the better candidate.
TL;DR Manbagi's interactions with Tadano are basic, while her character is anything but.
I don't really want to see people have full on wars over who's the best pick for him because in all truth, both of these girls are well-designed in their own ways and likewise have different flaws that hinder their matchup with Tadano. A lot of the alternate ending ideas proposed through comments have been interesting to me, no matter which ship they chose (or in some cases, even none), and I hope people take this message as a means to understand what both sides of the argument offer to the table in terms of "best girl". Regardless, I think we can all agree on one thing...
Tadano really needs to own up to that slip.