ok. I just tested with Garmin Mobile XT 5.00.20wp with HD2 locality set to CHINA.
no offset issues. but even with chinese support, no text shows.
I have tried flashing my phone with hongkong firmware, Singapore firmware, and singapore firmware w/ extended chinese sim&trad fonts. still no joy with road names.

tested with Garmin765, no offset issues but it can read chinese text.