Thank you for making this thread, Saz! There really are a lot of unique challenges for the tubby Mando to overcome before he can pull off a good looking kit.
I am 6'2", close to 400lbs and I'd say most of that weight is in my gut. It's huge. I tried enlarged plates, but there are a lot of problems with that. Simply enlarging the templates doesn't work at all. Stretching them doesn't work either. We're not just taller than the Fetts or wider but far more 3-dimensional. When you enlarge the designs you run into certain spacing and alignment issues that are hard to correct.
To be honest, if you're a big guy there WILL be a big exposed spot on your sides. Unless you try to modify your back plate to wrap around to the front or try some side plates or entirely new designs, the traditional Modern Era armor will leave that exposed area that Ghostwalker is talking about.
The way I worked around it was fairly simple. I used a shoulder cape on my left side that covers it, and I keep my weapon in my right hand so my arm is usually bent or the weapon helps to obscure the lack of armor.
It's not a cheat because we aren't making real armor. We're making costumes, and costumes are supposed to look good. You gotta do what you gotta do to look good.
Something else I tried is... less conventional. I've not talked a lot about it because I'm not entirely sure it's a great idea for everyone. It can cause you to overheat because it's another added bit of insulation to an already hot costume. On the other hand, I'm so enormous and out of shape and covered from head to toe in animal skins and a thermal jump suit, I'm constantly on the verge of overheating.
I made a fake chest out of an old shirt, styrofoam and duct tape.
I made a manzier. Or perhaps it's a bro? I took some styrofoam sheeting and sat it over my chest, resting on top of my bulbous gut. I proceeded to sculpt a fake chest that was fairly realistic and helped to bulk up my my upper body so my torso would be less pear shaped. This prevents the look I've seen a time or two where the ab plate seems to sit on top of your belly.
Once I had it shaped, I used duct tape to tape it onto my shirt, then folded the shirt over the foam and taped it all again. It's withstood a tremendous beating but it smells fuuuunn-ky. I still have full mobility and it's actually very comfortable.
Next, as has been mentioned, I've also used a girthbelt to cinch in my belly a little. And my ammo belt sits lower on my hip, basically under my belly, and the pouches help to make the gut less defined. It's less obvious that it's a big gut.
Here's a few pics of my kit: