Multitexture does not save UVs back to the OBJ. Instead, it creates a proprietary .TEX file that stores the UV coordinates. To get your map back into your game engine, you use a third-party script (like mt2obj.exe or a custom Python script) to inject the UVs back into the original mesh.
Output = R2
This is where you add the subtle differences that make a floor look truly authentic: multitexture 2.04