Just a heads up, it looks like the list on the start page at some point begins using the same previews for the different templates (despite having unique names). EG "placeport", "stereotherm", "conlangery", etc. all have the same preview for the templates. It seems like there are about 6 themes shown before this occurs. This seems to occur on both Chrome and Firefox.
FWIW, does seem pretty cool though, thanks for sharing!