Unless your league mandates a site (for example TAPPS gives the higher seed team option to host the first round game), almost EVERYTHING is negotiable for playoffs.
A friend of mine once told me that when he was coaching in UIL, one of his opponents wanted to play their playoff game at their home field and insisted on a coin flip to determine the home field. My friend, a disciple of tradition, wanted a neutral site. So he told his opponent, located in Central Texas as he was, that for that weekend, his home field was going to be Ysleta High School in El Paso. The opponent quickly decided a neutral field would be better.
There was one time, when we had a playoff game at Seguin Lifegate, that our opponents and I agreed that we should play at one or the other team's field. The options for a neutral site were going to be fairly close to one or the other school and instead of paying for a neutral site, we may as well play at one of our own fields. So, we agreed to flip the coin -- the winner got home field, and the loser arranged for officials from their home chapter.
When schools are from different areas, officials are often brought in from distant chapters. Sometimes, districts choose other chapters to call their games. Several years ago, the Austin 5A basketball district decided that the Austin refs were too familiar with some coaches and players, so they chose to have officials brought in from the Waco and Houston chapters to call their varsity games.
Listen, a meeting of CIA and KGB spies to trade captured spies have nothing on a Texas high school football playoff game meeting to determine game details.