i4oled just got bluetooth support. Wacom Intuos4 WL supports 4-bit images over USB connection, but only 1-bit when connected over bluetooth. i4oled now supports both with --bluetooth switch. Example usage:

i4oled -d /sys/class/hidraw/hidraw0/device/oled5_img -t "Alt+Ctrl" --bluetooth
   
i4oled -d /sys/class/hidraw/hidraw0/device/oled7_img -i help.png -b

And that's how it looks on the device:

Wacom OLEDs ovet bluetooth