Belts (and inserters) can only be placed facing north or east
Mods introducing new content into the game.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Can you add the multiple forces support? Every force has another direction to grow the factory.
I don't know how to make different settings on a "per force" basis; only "per player" or globally. If you know a reasonably simple way to support multiple forces like you have in mind, let me know how one would implement it and I'll consider it.
If not global[force_name].direction then global[force_name].direction = math.random (1, 4) End