I have MIUI 1.7.22 Italian installed on my HD2 running from SD card.
I found that there is version 1.8.5 available from the MIUI updater program on the phone. However, even if I download the ROM it doesn't get installed. It asks me to reboot in bootloader mode, so I suppose it works only with NAND-installed ROMs.
Do you know if it's possible to upgrade MIUI to 1.8.5 when running from SD card possibly without erasing all data on the phone?
It took me some time to customize desktop.