You do not need to get too caught up in the details. As I understand it, you are simply looking to make sure the game makes some progress and the person will eventually lose if they quit playing. "Correspondence -- Leisurely" will meet those needs. If you want to make sure a general pace of at least a few moves a week, with the possibility of a week or two off for vacation, then use "Correspondence -- Tournament".
You do not need to get too caught up in the details. As I understand it, you are simply looking to make sure the game makes some progress and the person will eventually lose if they quit playing. "Correspondence -- Leisurely" will meet those needs. If you want to make sure a general pace of at least a few moves a week, with the possibility of a week or two off for vacation, then use "Correspondence -- Tournament".