In the final fixes loop for foreign road tiles, I think you replace the collision layer with {transport_drone_road} instead of adding it. You also overwrite the item's place_as_tile.condition with its shared non-inverted {water_tile = true} condition. I have some tiles with other collision layers that need to be retained, and need to keep the water tile flag (don't ask). So I had to post-post fix that after your final fixes ran to repair the layer and water tile flag. It isn't the end of the world, but if it won't break it for others, could you leave the water tile flag alone and add to rather than replace the collision layer? FYI the affected logic is in Transport Drones on Asphalt 0.2.2 (about to be uploaded).