I just removed ability to generate world from blueprints because it was far too slow. I think you have to understand how the plugin works to create a good generator, so have a look at this.
Terrain size is only limited by integers limits. For now it’s 8192 * 8192 * 8192, but it could easily be increased by using int64 instead of int32.
Resolution (LOD) is limited by performance. I’m currently doing optimizations, and then I will post a video showing performance limits.