Save Wysiwyg content as post_content

add_action( 'init', function () {
    // Remove the editor for the post type.
    remove_post_type_support( 'post', 'editor' ); // Change 'post' to your custom post type.
} );

add_filter( 'rwmb_meta_boxes', 'your_prefix_register_meta_boxes' );

function your_prefix_register_meta_boxes( $meta_boxes ) {
    $prefix = '';
    $post_id = filter_input( INPUT_GET, 'post', FILTER_SANITIZE_NUMBER_INT );
    $post_content = get_post_field( 'post_content', $post_id );


    $meta_boxes[] = array (
        'title' => esc_html__( 'Code Snippet Before', 'text-domain' ),
        'id' => 'code-snippet-before',
        'post_types' => array(
            0 => 'post',
        ),
        'context' => 'after_title',
        'priority' => 'high',
        'fields' => array(
            array (
                'id' => 'content',
                'name' => esc_html__( 'Reason for snippet', 'text-domain' ),
                'type' => 'wysiwyg',
                'desc' => '###Why did I need to use this?
This field is also used as the Excerpt for the post.###',
                'class' => 'reason-for-snippet',
                'std' => $post_content,
            ),
            array (
                'id' => 'what-it-does',
                'name' => esc_html__( 'What It Does', 'text-domain' ),
                'type' => 'wysiwyg',
            ),
            array (
                'id' => 'actual-code-snippet',
                'name' => esc_html__( 'Actual Code Snippet', 'text-domain' ),
                'type' => 'wysiwyg',
                'sanitize_callback' => 'none',
            ),
            array (
                'id' => 'before-the-snippet',
                'type' => 'single_image',
                'name' => esc_html__( 'Before the snippet', 'text-domain' ),
            ),
            array (
                'id' => 'after-the-snippet',
                'type' => 'single_image',
                'name' => esc_html__( 'After the snippet', 'text-domain' ),
            ),
            array (
                'id' => 'custom_html_sbvmvz193m',
                'type' => 'custom_html',
                'std' => '<style>#wp-content-editor-tools{background:none;padding-top:0;}</style>',
            ),
        ),
        'style' => 'seamless',
    );

    return $meta_boxes;
}

// Set the value for the 'content' field.
add_filter( 'rwmb_content_field_meta', function() {
    $post_id = filter_input( INPUT_GET, 'post', FILTER_SANITIZE_NUMBER_INT );
    return get_post_field( 'post_content', $post_id );
} );

// Do not save to post meta.
add_filter( 'rwmb_content_value', '__return_empty_string' );