Just want to add something. When updating my Glo to 2.8.1, if the light is on and set to 1%, when the Kobo enters (manually) the sleep mode, when woken up, light does not come back. Starting 2%, it's fine. Which is for sure annoying when reading in a pitch black room...

Then, all updates above 2.8.1 still have the bug.
Seems that the 2.8.1 is the update that generates the bug. If goes direct from 2.6.1 to 2.10, no problem.
I did a factory reset then updated manually to 2.6.1 and never sync again. Installed the hack, and it worked like a charm.
Just wanted to try and updated to 3.1.1. Happy, the 1% light bug is not here and the night mode hack still works (after reinstallation).
For those who faced this bug. You just need to follow these steps (I found them in the forum, somewhere and am not able to find it again). If this can help...