I have painlessly upgraded my KN7K up to v1.6. The upgrades so far had only one feature which concerned the German HELP screens, otherwise they were universal. I have also upgraded my Digital Camera's OS on one occasion and will upgrade my MP3 player when necessary. That is the whole idea behind OS on flash EPROM.
BTW, who says that the upgrades were unofficial? And, again, who says that the majority of owners have not upgraded. I have personally distributed many copies of the upgrade files, along with an set of English instructions, and been thanked for them.