Problem/Motivation
From #3041143-14: Add ARIA group roles to Layout Builder UI
The Save Layout and Discard Changes buttons are only at the top of the custom layout, which means that the user will have to backwards tab all the way to the beginning of the customizable section in order to save their layout. I would suggest replicating these buttons at the bottom of the customizable layout area, as well, or providing the keyboard user some other means of getting to these buttons quickly once they have reached the final section of their layout.