The problem with 2 1/2 inches here is it would have to be mowed every other day, (often it gets it) in order to stay within the 1/3 rule. 2" is really no problem. You can go down to 7/8" with experience especially where equipment maintenence is concerned. It takes a balanced sharp blade to cut the thick stuff and technique. With an understanding customer and the right budget, it can be done. Keep the ball in your own court.