Hi, I might be giving
misinformation but maybe this will help:
unofficial v. 1.8 20130114 firmware was said to allow for dimmer front light output at the lowest setting. I had it installed a while ago and the light seemed dimmer to me than with the firmware I have now (latest Booxtors), but it might be just a subjective impression since I don't have a measuring instrument. You can try installing yourself and/or comparing the content of the zip files.
Here's the
download link.