Yup, it wouldn’t. It would work only in case you make a separate 3d object (a puddle) and export it into the sim as a 3d scenery object. That could be done for smaller ground details, but not for large ones due to earth irregularity and your mesh diving into the ground/Z-fighting. For truly ground materials such as projected mesh and aprons/runways metal channel is not taken into account at all and is effectively wasted. I hope they will take a look at this at some time, pity that SDK stuff both in bugs and wishlist sections does not get any significant number of votes and attention.