Blocks the total comment link for WP

wp_block_comment_length.php

<?php
add_filter( 'preprocess_comment', 'bt_preprocess_comment' );

function bt_preprocess_comment($comment) {
    // the comment_content column should never by greater than 64kb
    if ( strlen( $comment['comment_content'] ) > 65534 ) {
        wp_die('Comment is too long.');
    }
    return $comment;
}