This really is not that hard, the coaches are a heck of a lot more likely to know who the best teams are than some random people in a dark room who may or may not have CFB knowledge and/or an agenda. So, at the end of the season, the CFP committee or BCS or whatever ranks who they believe to be the 12 best  teams 1-12. if you have to throw in certain conference champs (why the Mountain West is in and not the MAC champ is still an unknown) then they rank the 12 teams that are in the playoffs 1-12.

Then, we have a live televised event where all 12 coaches (via zoom or whatever) are present and the bracket is presented with times, dates, and venues, but no teams.

The highest seed gets to pick a venue or pass. The next highest has the same option and so on. If the number one seed passes and the number 2 seed picks, the next pick goes back to the number one seed to either pick or pass again and the next pick goes to the next highest left on the board. After every pick (not a pass) the next pick goes back to the highest ranked seed that previously passed. The lowest seed in each round must pick a venue.

Hypothetically, 1-6 pick their separate venues, 7 must now pick which opponent he wants to play or he could potentially pass which would give him more limited options after someone lower seeded picks after him. 

Let’s say coach #6 hates coach #2, he could choose to play him in the first round if cioach #2 has already picked a venue.
 

This would likely lead to 1-6 picking a venue and 7-12 picking who they want and do not want to play. This would clean up any miss-seeding of the original 1-12 as teams would be choosing who they want (and do not want ) to play. It would make great TV as we would see who wanted to play who and who ran from certain teams (maybe jumping to the other side of the bracket.

This is how Ohio high school basketball playoffs were seeded years ago.