This sounds terribly inefficient. Why include the tiles as part of the design? Why not instead have a specification about what kinds of tiles are supported and

This sounds terribly inefficient. Why include the tiles as part of the design? Why not instead have a specification about what kinds of tiles are supported and how they should be laid out instead (just an interface)? Then other projects could take care of providing designs for tiles... Tile providers will need to change to adapt any changes to the core layout, but the core layout doesn't need to change often since the fickle parts are not part of it.