It's my opinion, since there's no historical data to extrapolate from, that a 1-loss Champ from any of the Power 5 will be good spot to get in. Having that extra game will be big over a 1-lose team that was at home for the conference championship game. As for a team that got their first loss in a Conference Championship game? That's a lot of variables but we, as humans, tend not to feel strongly about teams that just lost so I would not expect a team that just lost a CC game to get in over a team that just won theirs without some sort of mitigating circumstances.
I feel a 12-1 Ohio State is in the playoffs. However, there's still a lot of football to be played and no certainty we end up 12-1.