At the origins of TLP, we did not have access to gap. This is probably why we had to write two classes tlp-button-icon and tlp-button-icon-right to assign the correct margins for buttons on the left and right of buttons. Since we can now use gap, we can completely remove the CSS class tlp-button-icon-right, because there is now no difference, tlp-button-icon is sufficient (it just sets font-size now).