alright, I'm not sure exactly how to set language attributes... is there anywhere other than the metadata to set the language? maybe I'm missing that.
So I did a little test, took an article about wolves and put it in a UTF-8 text file loaded it into Calibre and changed the metadata to be in chinese then had Calibre make an AZW3 file with the desired font.
the result is interesting, for both the txt and azw3 file the kindle treats a group of characters as one long word...
perhaps it's a bad example... but I do have other .mobi files that the dictionary works for the mobi, but breaks when converted.