Better COM Mod [Besiege v0.4]

Hi, nice mod!
I tried it with 0.42b and it doesn't seem to work properly. When I add a Ballast and chance its weight, the mod shows weird numbers as mass. Actually if I play around with the mass of the Ballast, sometimes the shown vehicle mass decreases although I increase the mass of the ballast. Unfocussing the ballast mass input field doesn't change anything. The COM does actually update and seems to move correctly, but I am not sure since the mass isn't shown correctly.

Edit: Using Easy Scale mod and scale the ballast doesn't effect the shown coordinates for center of mass.