You need first to have an ultra simple way to control borders (All borders) on all elements
— A single place that control the Size, color and style of any elements border —
This is what 90% of user will ever needs & use.
and you also need to acces the fine control of all sides of a border for the 5% that need them
You don’t FORCE the 90% to have to enter ALL THE PARAMETERS ON ALL BORDERS SIDES each time they want to set a border. It make no sens ....