THALL
The reason its 4% is in case you are off grid for an extended period of time. Apparently that last bit is the 'keep alive' for the battery management system and some other technical reasons. It isn't user accessible.
This is not a reserve like a "storm alert" managed reserve. That is user acessible and managable now. This last bit isn't so you cant bank on using it in any circumstances.
The only time you will see it go lower is if you recalibrate the battery. At that time the system needs to hit the buffers at both ends, so not an everyday occuance
I will take this back to discuss internally as i see the confusion, but do wonder if we would get confusion the other way?