Yeah mass is not weight. So it doesn't make an object lighter. There is one way to make soldiers jump real high, almost like a diving board. You place an object and scale it to a larger size, and when a soldier stands on top of it, they can jump much higher distances than normal. And if you were you scale an object down, a soldier could slide across the object like ice. These are both actually bugs in the game due to the mesh being stretched or squeezed down, causing problems with the way soldiers walk over object mesh.
The code for scaling an object is:
Object.geometry.scale x/y/z, where x,y,z are decimals. (scale down=less than 0, scale up=greater than 0)
Anyways, you could always try that.
