It won't happen, because of the monopoly at the top.

Have all the rankings, conference champ rules, etc. Stay the same, but have all conference champions that are in the playoffs get selected for byes based on the conference bowl results from the previous year. Best win% first, then if there's a dispute, best head to head %, then higher ranked. ND (ACC) and other independents would have to declare conference tie-ins of some sort.

NOW, when an SEC team plays an ACC team in a bowl, it has future implications. And bowls can adjust tie-ins accordingly.