I would focus pre season on simply listening and patterning him. DO NOT CALL TO THIS BIRD BEFORE SEASON.

As you indicated, usually most birds have 2-3 areas that they go to immediately after flydown. Identify those spots clearly before season. During season, once I knew his early morning hang out spots, I would focus on these areas. I would probably put up a decoy, and let out a few clucks and purrs and fake a hen flydown in this area and then shut up and watch carefully and listen for his flydown. If you identify his hangouts, and put the time in you will end up with a shot at him.

You kill these types of birds by being where they want to go, not by calling them in to you. Pattern him and spend time in those spots with VERY minimal calling and he should be yours.