This is going to be a terribly difficult adventure.
First you'd want to get Focal's freq response curves ON YOUR BAFFLE, which is probably impossible, so you'll have to measure it yourself. Oy.
Then try to find a tweeter that is slightly different in the ways you would prefer. Then mount it sturdily somehow, and redo the crossover and resistor-padding as necessary to get a fine frequency response and reasonable impedence plot to work correctly and sound great on and off-axis. Phew!
First you'd want to get Focal's freq response curves ON YOUR BAFFLE, which is probably impossible, so you'll have to measure it yourself. Oy.
Then try to find a tweeter that is slightly different in the ways you would prefer. Then mount it sturdily somehow, and redo the crossover and resistor-padding as necessary to get a fine frequency response and reasonable impedence plot to work correctly and sound great on and off-axis. Phew!