Use Font Awesome icons from your own host/server. Update the latest releases from GitHub.
Choose the major version and install the latest minor version. For example: Choose major version 6, and install the latest of 6.x.xx. 
Currently supported for version 4, 5, 6, 7.
This plugin did not use CDN (content delivery network). If you want to use CDN, please use official Font Awesome plugin instead.
You can dequeue duplicated Font Awesome handles from other plugins or themes to prevent conflict.
You can disable enqueue from this plugin in case you would like to do it manually. 
To get asset files for manually enqueue, use this code.
<pre>
if (function_exists('rdfontawesome_get_enqueue_files')) {
 $result = rdfontawesome_get_enqueue_files();
 if (isset($result['css']) && is_array($result['css'])) {
 $faVersion = ($result['faVersion'] ?? false);
 $i = 1;
 foreach ($result['css'] as $css) {
 wp_enqueue_style('myplugin_fontawesome_' . $i, $css, [], $faVersion);
 ++$i;
 }
 unset($css, $faVersion, $i);
 }
}
</pre>
To get URL base of the Font Awesome assets for use another files, use this code.
<pre>
if (function_exists('rdfontawesome_get_public_url_base')) {
 echo rdfontawesome_get_public_url_base();
}
</pre>
Tested up to PHP 8.5.
Font Awesome files are belong to https://fontawesome.com

Rundiz Font Awesome

Use Font Awesome from your host and update from GitHub.

Farhad Sakhaei

DediData

ParsMizban

WordPress + TinyMCE + Font Awesome + Bootstrap 
This plugin extends the buttons on the Visual Editor toolbar.
It includes 20 plugins for WordPress Editor (TinyMCE)
<ul>
<li>Insert Many Icons from Font Awesome Set easily, Change their Size or Border!</li>
<li>Support HTML Templates (We will add many pre-designed templates soon!)</li>
<li>Insert Table of Contents based on headings</li>
<li>Insert sample of codes, and colorize them</li>
<li>Insert emoticons</li>
<li>Change Text Colors and Back Colors</li>
<li>Great Context Menu</li>
<li>Print, Paste as Text, Find and Replace, Insert Media, Special Characters, Horizontal Line, Read More Tag, Page Break Tag, Anchor, DateTime</li>
<li>Support for creating and editing tables.</li>
<li>Search and Replace in the editor.</li>
<li>Show Blocks, Show Invisible Characters</li>
<li>Insert predefined styles and Clear Formatting</li>
<li>More options when inserting lists.</li>
<li>Ability to set Font Family and Font Sizes.</li>
<li>Full Screen and Preview Options</li>
<li>And many others.</li>
</ul>
Validated by: 
https://wpreadme.com 
https://wordpress.org/plugins/developers/readme-validator

Advanced Classic Editor

This plugin has the clean codes and has the best practice of doing the process.

Clearn Source


This plugin has only 1 competitor: "Advanced editor tools" by Automattic. I mention it because I tested both. Atomattic's only adds the table and top menu capabilities, while Advanced Classic Editor also add icons, buttons, alerts, and other bootstrap related stuff to make your life easier.



Also I just reported an error with font-awesome, which analyzed by plugin author, fixed and released within hours by plugin author = KUDOS to him!



Thanks to this plugin, I could get rid of three others which only added bootstrap shortcodes and tables. I cannot thank this author enough. This is real good and brings TinyMCE back to life again.



It surely can be expanded with more bootstrap stuff like other premium plugins, but that's the cost of free stuff and I'm willing to keep it that way.


Best TinyMCE addon

Advanced Classic Editor - Your powerful WordPress editor, Insert many Icons, Insert Table of contents, etc.

Rundiz Font Awesome vs Advanced Classic Editor