Owning a α7II and a α6300, I noticed my α7II doesn't have an accurate electronic level gauge compared to the α6300 which is really accurate on a flat surface. The α7II is slighty offset on the rolling axis by 0.5° in the similar situation, leaving out the green zone.
I really love and enjoy these cameras, and sending the α7 back to a repair centre might be too much for this little default...
When shooting, especially with the α6300, the levels help me a lot in my composition, avoiding me to rotating and cropping during my post productions. Unfortunately, with the inaccurate levels of the α7, I have to correct more often during the post prod process (and then, crop a bit).
So my suggest for the future firmwares : adding a new option to let the user to re-calibrate manually the electronic gauge level.
This would help the user to be sure composing to an accurate horizon, or even composing with it's own desired levels.
Olympus does have this calibration adjustement option on their E-M1's, why not Sony?