I did some tests with the new 3.4 firmware for K3 (Keyboard) and was pleasantly surprised to find out that the dictionary lookup algorithm now finally supports non-Latin input languages. (I only tested it with
Classical Greek, Russian and Arabic dictionaries, but other languages should be supported, too.)
Depending on the size of the dictionary and whether it has an inflection index, looking up words in non-Latin languages might take a bit longer but it works. However, since the dictionary format hasn't been updated, Arabic letters are displayed as LTR text.
FW 3.4 also fixed the French word segmentation problem mentioned in this
post, which made it impossible to look up words like "l’étoffe," and the dictionary window displays up to three lines now.
This might make a used K3 (Keyboard) a cheap alternative for Kindle users interested in foreign languages.
I cannot recommend it for Arabic though, because it only supports text without vowel signs.