Hi. I wrote a json converter to obj. https://github.com/Luvideria/mcfgJSONtoOBJ
It's not super great, but It's at least more convenient for blender use.
It's pretty easy to customize as well.
Cool! Does it work with the latest version of MFCG? I tweaked JSON there a little. Unfortunately, I don't know Python and I don't have it installed to check it myself.
I downloaded a new example and it looks like it works, see the README on github, I put an image. There is no city walls or water body yet (because I didn't need it) but if anyone is interested in it, I can implement it. I think being able to re-color every building is pretty neat too.
If you send me a file with all the new features I can also implement/update it.
Keep up the good work :)