I've made several sails over 50 sq m, and it seems to me that there is a valid reason to use Roger's hinges at one or two battens in these larger sails, to make the handling easier. They are certainly more work to make, so there has to be a good reason to use them. A large sail is heavy and bulky, and to be able to move it around in two or three separate pieces, both when making it and when rigging it, has appeal.
But in smaller sails, I can't see any good and sufficient reasons to use them. I had no trouble in making my 22 sq m sail, using soft cloth, in my living room. Your proposed sail, Jami, is towards the bottom end of the scale of size, and whatever methods you use to join panels and add the pockets, I can see no reason to go for the 3H method.
Going up to Asmat's size of mainsail, twice as big as mine, I can see that it would be justifiable to put in some extra work to make it in two sections, joined by the 3H method. Going right up to the very large size of mainsail that might be wanted on the 50ft boats discussed recently, I would be tempted to split the sail into as many as four sections.