They should force all P5 Conferences to play 9 conference games. The SEC should have nothing to worry about because the the bottom half of the SEC is a joke. Any gain in win loss record for a PAC 12 team playing an 8 game Conference schedule would be more than offset by the inherent media bias for the CFP. They just really need to expand the play-off to 8 teams.
And if the PAC-12 went to an 8 game conference schedule, that would open a window for an end of season game against BYU. BYU plays all its tough games early, so they would be relatively healed up by the time the Utah game rolled around. In contrast, Utah would be beat up and playing a meaningless game. I would not expect good outcomes from that scenario.