Thank you for clarification on the units. I am importing the data to Unity for further generation into 3D content.
Would be nice to have more data in the JSON file, like voronoi cell boundaries and maybe a cell content type, so that for example wards and different building types can be distinguished from each other. It's also missing some features like piers and those town square "wells".
Maybe some proprietary JSON or XML formatted export file would be better, so you wouldn't have to conform to the rigidity of the GeoJSON format. But this is probably what you are doing as you were talking about metric units.
Thank you for creating this great generator, I'll be waiting for future updates.