order of most to least in hypothetical playoff matchups, I guarantee 18 or 19 of them would prefer to play BYU over Bama, Georgia (assuming they lose to Texas), Miami, S Carolina, Ole Miss, Ohio State, Penn State (if they lose to Oregon), SMU (if they lose to Clemson), Boise State, ND, or Tennessee.
It might be a push with Indiana, but they get the in over BYU with only 1 loss.
There are paper arguments to thinking BYU has a shot. If they don't screw up vs Kansas and then lose a close B12 CG at 11-2 they have a better case.
But realistically BYU isn't one of the best 12 teams. And they certainly haven't played like it in November when it matters.
Full disclosure - I think I the SEC is overrated, the system is biased, and I hate that the B12 is under valued this year esp compared to the likes of the B1G. But fandom aside, BYU hasn't merited a CFP at large bid with their resume.