Transfers are the issue. Nothing wrong with kids going where they want to go, but they create the imbalance. The issue isn't public/private, metro/suburban, rich/poor. There are schools that get them and schools that don't. There needs to be a system that groups teams based on that.
Have an Open Division, but make it based on the number of incoming transfers.
All FHSAA teams will be places into districts based on geography and enrollment (pre Metro/Suburban split). 8 classifications (Rural + 1A - 7A), 16 districts per. District champions are automatic qualifiers and the remainder of the playoff qualifiers are determined by Maxpreps ranking. At the conclusion of the regular season, the 32 teams with the highest number of incoming transfers (tracked by GA-4 forms) are placed into Open Bracket. If a district champion is moved to the Open Division, the 2nd place team becomes an At-Large qualifier, assuming they are not in the Open Division. If they are, then the 3rd place team becomes an At-Large qualifier, and so on. If there is a tie for the 32nd most incoming transfers, the team with the higher Maxpreps ranking moves in to the Open Division.