Cliff Seal

Simply put: this plugin gives the Editor role access to edit “theme options”, which includes:
<ul>
<li>Appearance > Widgets</li>
<li>Appearance > Menus</li>
<li>Appearance > Customize if they are supported by the current theme</li>
<li>Appearance > Background</li>
<li>Appearance > Header</li>
</ul>
Instead of adding this capability by hand on each client site, just install and activate this plugin—it keeps your <code>functions.php</code> file clean, and keeps this type of functionality where it belongs.
The capability is added to the role once (on plugin activation) and removed when the plugin is deactivated.

Editor Theme Options

Allow editors to access theme options in the Appearance menu.

SEO Neo

The REST API Extender is a WordPress plugin that extends the functionality of the WordPress REST API.
It provides two main features:
<ol>
<li>Permalink Options Management 
This plugin allows you to update the permalink settings of your WordPress site via the REST API. You can change the permalink structure, category base, and tag base using a simple POST request.</li>
</ol>
To update the permalink settings, send a POST request to the following endpoint: 
/wp-json/raext/permalink-options/v1/settings
The request body should include the following parameters:
<ul>
<li><code>permalink_structure</code> (string): The new permalink structure.</li>
<li><code>category_base</code> (string, optional): The new category base.</li>
<li><code>tag_base</code> (string, optional): The new tag base.</li>
</ul>
Example request: 
POST /wp-json/raext/permalink-options/v1/settings 
Content-Type: application/json
{ 
“permalink_structure”: “/%year%/%postname%/”, 
“category_base”: “categories”, 
“tag_base”: “tags” 
}
<ol>
<li>Theme Installation and Activation 
The plugin also enables you to install and activate themes from a remote URL using the REST API. You have to provide the theme URL, stylesheet, and slug, and the plugin will handle the installation and activation process.</li>
</ol>
To install and activate a theme from a remote URL, send a POST request to the following endpoint: 
/wp-json/raext/theme-manager/v1/install
The request body should include the following parameters:
<ul>
<li><code>theme_url</code> (string): The URL of the theme ZIP file.</li>
<li><code>theme_stylesheet</code> (string): The stylesheet of the theme (e.g., <code>twentytwenty</code>).</li>
<li><code>theme_slug</code> (string): The slug of the theme (e.g., <code>twentytwenty</code>).</li>
</ul>
Example request: 
POST /wp-json/raext/theme-manager/v1/install 
Content-Type: application/json
{ 
“theme_url”: “https://example.com/themes/twentytwenty.zip”, 
“theme_stylesheet”: “twentytwenty”, 
“theme_slug”: “twentytwenty” 
}
Developed by the creators of <a href="https://seoneo.io/" rel="nofollow ugc">SEO Neo</a>
<h3>Permissions</h3>
Both the permalink options management and theme installation/activation features require the user to have the <code>manage_options</code> capability (an administrator role).

REST API Extender

The REST API Extender is a WordPress plugin that extends the functionality of the WordPress REST API.

Editor Theme Options vs REST API Extender