I'll simplify if. You can use the tool if you want to verify it, but the tiebreaker is way less complex than people are making it. These are the scenarios a 1 loss BYU doesn't get in. That's pretty much it

1) KSU beats ISU and ISU is clean the rest of the way
2) KSU beats ISU and ISU is clean and CU is clean

That's pretty much it. If ISU beats KSU at home, BYU wins a 2 way with CU or if ISU weren't clean ISU and BYU would go by virtue of KSU being the best common opp and CU losing to them. CU is a longshot if you look at anybody's odds to make the B12 champ game because they basically lose every tie breaker