Understood, currently that isn’t available as an option. Tt is possible to do, but there are some challenges.
One of the trickiest things about writing and supporting this plugin is keeping an up to date list of all available icons. In previous versions of this plugin the FontAwesome CSS itself was parsed with regex to ‘scrape’ out all of the icons to generate an inventory.
As FontAwesome got more complex with all of the different icon sets this problem became much more difficult to fix with a regex. Thankfully the 5.x versions of FontAwesome ship with a YAML file that details all of the icons in each version of the font.
I wrote a companion plugin that I run on my own web server to keep an up to date copy of that YAML file for both free and pro version in a reliable location hosted on GitHub and CDN’d through jsDelivr. The plugin then parses through this YAML and caches the list of icons in the database.
A manual enqueue would require that the user also provide that YAML file in some way, possibly placing it in a directory of the plugin so that it can be read. There will also need to be a way to invalidate the cached icon set if/when the YAML file was replaced with a new version.
I’d be interested to hear from more users if this is a feature that more people would like to see before I invest the extra dev time to make it happen.