I did some decal painting on a Hexagon 1.21 OBJ mesh I had imported into 3D-Coat 2.10. And when I exported the painted mesh back into Hexagon, the edges around the windows were just slightly off. Just enough so that the windows didn't fit right.
I tried everything I could think of to preserve the original mesh between the apps. Then i tired the last thing with was to "Export low-poly mesh with original positions". Since I wasn't smoothing the mesh on import, I should not have been exporting a mid-poly mesh.
So now I can paint diffuse colors on my meshes all I want without the worry of them exporting with the wrong size or in the wrong location.