Why does the gimbal move when updating firmware?

[30secs]

And I wonder if updating the firmware on a leveled surface might help with the tilted horizon issues..

 

[bbfpv]

likely to test/verify its range of motion and make sure everything is ok. I don't believe it saves any values so setting it on a level surface would probably do nothing (though as you are aware is generally good to do any time one is messing w/ settings).