Hinaloe

This plugin allow your site’s comment form makes ajax — non move/reload when user (including both subscriber, normal viewer, and admins too) post comment!
Most themes supports this plugin, but if your theme’s <code>class_form</code> have not <code>comment-form</code>, this plugin non supported.
And this plugin only can use for Pure WordPress Comment form. 
so, its not able to be used with like Jetpack comment form and other original/outside comment system/form.
Feature
<ul>
<li>post comment with ajax</li>
<li>Lite — this plugin only using a little of jQuery feature to modify DOM, and very tiny js & PHP code.</li>
</ul>
Require
You have to install <a href="https://wordpress.org/plugins/rest-api/" rel="ugc">WP REST API v2</a> to use this plugin if your site is running on WP 4.4-4.6.

ajax Post Comment

Post comment form on frontend tobe ajax using WP REST API Version.2

ChazUK

Returns Yoast post or page metadata in a normal post or page request. Stores the metadata in the yoast_meta field of the returned data.

WP API Yoast SEO

Returns Yoast post or page metadata in a normal post or page request.

ajax Post Comment vs WP API Yoast SEO