My suggestion may sound more radical ..
I suggest that for every pairing: e.g Player A vs B they play two games .
First Player A chooses ANY game (it can be his own), then Player B chooses
his. Player B shall play white (or have the option to play first) in player
A's game, and Player A plays white in Player B game.
We can restrict it so that no player can choose to play the same game more
than twice for the whole tournament. Also, the rules of the particular game
chosen must be clear to the opponent.
To me, this makes more sense because every player gets to play his/her own
game as well as opponents game.
And there will be a larger amount of game types being played, with the
added benefit that players can playtest their own games.