I expanded the back about 4 inches. Getting the neck shape was a pain, but it's so comfortable now. 36lbs isn't that bad when it's draped correctly.
Also the armpits are deeply gusseted. I can bring my upper arms up to shoulder height before the shirt starts to lift.
Please realize that the Mailmaker's guide can give you a shirt tailored exceptionally well to your body, by which I mean it will move with you through your entire range of motion, but it also will be near the minimum amount of material (and therefore weight) to do so. The 3 points I brought up in my first post are enough to make a decent shirt, built like a T-shirt. If your chest & belly are about the same size, T-shirts fit great. If they are different, you either deal with it fitting in one area and being tight in another, or going up in size and fitting in one area and being loose in another. Since maille is like a Chinese finger trap, it never really gets loose; it just squeezes to the body and gets longer. My first shirt (16 ga. x 1/4 galvy, short sleeves, mid-thigh) was made in this manner, and works fine, at a weight of 28 lb. It's just heavier than it needs to be, and I could probably shave off a couple pounds.