When tiles like rails and sloped ceilings are placed in certain combinations they clip through each other. An example would be a balcony I had where the railing clipped through the sloped ceiling, giving it a very unappealing look.
The clipping needs to be looked at, but specific to railings there adding half rails and "Open" rails such as Bhutan has would be a bonus. Some stairways take up only a portion of a tile's width, leaving large gaps in the rails that are both unsightly and potentially dangerous (safety first!). Rails that appropriately "fit" the stairs of their tile sets would be a big help in that regard, and half-rails would also be useful for other design purposes.
