"Multiple-Team Ties
In the event of a tie between more than two teams, the following procedures will be used.
After one team has an advantage and is “seeded”, all remaining teams in the multipleteam tiebreaker will repeat the tie-breaking procedure."
So after KState (or possibly Iowa State if their SOS is better than KState in the next 5 weeks of football). . . The remaining teams will repeat the tie-breaking procedure. . . and when you start from the top. . . BYU wins.