Hi Stuart,
The Fontawesome filter does not provide the icons and only seems to work with so-called Fontawesome-enabled themes.
While the icons can be called up using the link to the stylesheet, the filter did not seem to recognise that they ere available - at least on our system.
The themes that are in the list of themes that work with the filter all seem to have the icons embedded as fonts so I thought I would give it a try. Certainly, the icons do now seem to render with less lag than previously, although that might just be wishful thinking on my part.
Glad you liked it.
Malcolm