Making it flush with the drywall is an odd way to do it, usually it sticks out just the width of the tile. They could just set the tile and then another layer of drywall to bump the wall out to be flush with the tile. Probably the easiest way rather than framing in two different depths. Wouldn’t worry about the weight, 14lbs isn’t much across a spread area and if it’s fixed appropriately all the force is vertical which is going with the strength of the wall. This is American knowledge, so it’s possible I’m missing something