world size trivia:
The game actually requires worlds to be at least a certain size, or else we'd need to do a LOT of work in the rendering. The problem is your draw distance is about 1km, which is a 2km diameter sphere (lets say circle for now to talk about chunks), and the largest LODed chunk is 256m across which adding in a buffer there means in terms of chunks that get rendered you can be rendering in a worst case approximately 2.5km in a single draw of the world (so ignoring portals which are seperate draws). If the world were less than about 2.5km across, we would need to do a lot of work in the rendering to be able to support the fact that with wrapping, the same physical chunk can be in more than one place at once during rendering, and supporitng that wouldn't be easy by any means, not just the actual rendering itself, but all of the visibility/occlusion queries involved too.
Seperately from this, the world generation, and yes, even the texturing, requires itself certain discretised sizes for wrapping of the world itself, and of the block texturing, to work everywhere. The biggest LOD chunks are 256m across, which means the world size must be divisible by 256. Seperately, we have blocks whose texturing is based on 2x2 and 3x3 grids of detail, which means the world must also be divisible by 2 and 3. In total, it means our world size must be divisible by 768m... except there is something (that presently I cant remember), that requires divisible by 2 world dimensions at each LOD level, which means the worlds actually have to be multiples of 1536m so that the largest LOD level can be even sized.
Combining together, we get that the possible valid world sizes are multiples of 1536 starting from 3702m, so possible world sizes for the game to function are 3702, 4608 (the current worlds are this size), 6144.. and so on.
A seperate issue is then precision, which in testing starts to show up issues once the world hits a size beyond around 8000m I believe from memory (We already have many precision issues even with just 4608 worlds, particularly for rendering transforms, but these have largely been resolved now).