Is FontAwesome Pro supported?

Yes, in order to use the FontAwesome Pro version, download the latest icon package for the Pro version (FontAwesome v5 only) from https://fontawesome.com/ and upload fontawesome.min.css and the webfonts folder (and all its font files inside) to wp-content/drts/assets as shown below.

wp-content/
  drts/
    assets/
      fontawesome.min.css
      webfonts/
        fa-brands-400.eot
        fa-brands-400.svg
        fa-brands-400.tff
        fa-brands-400.woff
        fa-brands-400.woff2
        ...
        fa-duotone-900.eot
        ...
        fa-light-300.eot
        ...
        fa-regular-400.eot
        ...
        fa-solid-900.eot
        ...

You may also need to run the “Clear cache” tool from Directories -> System -> Tools.