One of the highest scores ever recorded at the Army's Jungle School in Panama (former Jungle School that is) was by an Innuit from Alaska. He was amazing and the heat didn't seem to bother him at all. The climate may favor a smaller frame, therefore the small size of the indigenous peoples.
Ontario may have changed their machete - UNFORTUNATELY! The older ones were unground, except for the sharpened edge, and I don't know how thick they were. The one I have here, is 1/8" steel, but the blade is flat ground to the spine, making it thinner as you move out (0.110" most of the way), still with a unground edge bevel though. It's really more thinned than beveled. The newest ones I've seen are the same, but have a ground edge bevel about 3/8" wide. These last suck for heavy wood chopping, since they bind more easily.
I've attached a pic of the edge I like to put on older Ontario's. It is about 3/8" wide and fully convex. It will cut for a very long time without dulling, since it's a very robust geometry. This particular machete parted 3 bundled 1" hemp ropes without too much trouble. Not bad for Rc50, 1095 steel. I lose about 5 Ontario machetes a year as a result of showing them to people, who then tend to leave with them...
If I could get Crucible steel to roll CPM-3V thinner, I'd make a few of what you describe, but would prefer to keep it in the 0.100-0.110" thickness range to allow for the convex edge. The benefits of this edge geometry when chopping dense material is substantial. The thickness you're speaking of would be OK for lighter brush, but might get whippy on heavy chopping. Fullers, like you see on some machetes would help that, but I would still prefer the more generally useful blade/edge geometry for the reasons given, even at the expense of a couple ounces in weight. My trail breaking days are long past...
The advantage of an Ontario over a high tech marvel though is that it can be reasily sharpened on a flat stone or with a file. I'm sure that's why they're the hardness they are because most of the world sharpens blades that way.