The border width setting comes close do doing what I want: to be able to adjust the empty space between the left border and the leftmost pixels of the text.

Instead of adding more empty space, however, that setting makes the border wider.

Can you add a setting (hidden or otherwise) to adjust the empty space between the left border and the leftmost pixels of the text?

(For RTL languages, replace "left" and "leftmost" with "right" and "rightmost", respectively.)