I believe adding the same numbers and configs for the armor bar, like what is added for the health bar, would be a nice addition.

As far as I know there are mods that add text next to the bars but the icons themselves aren't configurable.
Adding the same configs of the health bar to the armor bar (idk about a toughness bar although it seems similar to armor) would be very cool, but I don't know if it would be in your plans.