XF 1.4 Adding Font Awesome to Tabs Created by Add-Ons

Hey all,

I like to use Font Awesome icons to help illustrate what the navigation tabs mean within XenForo; however, I've got tabs for the XenForo Resource Manager and the Steam integration add-ons, but it seems there is no way to add a Font Awesome icon to their respective tabs. I went through Phrases and tried simply adding in the icon that way, but it does not work. I also looked at the template modifications but that does not seem to help, either. I'm almost positive that an add-on is causing a conflict with tabs as I had to manually edit the Navigation tab template rather than just the style properties in order to actually edit the tab styles, but that was a minor inconvenience. Does anyone know of a way to add Font Awesome icons to tabs generated by add-ons?

Here's a screenshot to illustrate:

Any help would be greatly appreciated.