I used to make charts for this series for fun, since it featured numerical affection levels by chapter. I have a whole spreadsheet for this series with charts lmao. I completely forgot to do it when the last chapter dropped. Here we go.
Note that for Otomore, we're setting her unknown affection level at 0. Ch. 81 suggests that this isn't the case and could very well be quite high, but we'll probably never know. There's probably a sharp change around that point though, considering what happens in that chapter. But it's movements between Kinjo and best girl that we're more interested in.
Kinjo's is generally steadily increasing, while best girl's shows more sharp increases/decreases. Both roughly track each other. In retrospect, you could say that the author set Kinjo up as the "coventional" route, i.e. predicting that she'll win wouldn't a controversial take. While best girl was set up as the wild card, whose affection level was set to track Kinjo's (or the reverse) to produce a feeling of tight competition.
Himekawa, meanwhile, stayed a bitch to the end. But judging by the latest chapters and assuming that lower positive levels of affection is the same as friendship-tier, then my guess is that her stated affection levels in the latest chapters may be inaccurate (to not show a very sharp increase towards positive levels, maybe) and she might have ended up being friends with MC at least.