Latest Post Shortcode 7.0

Here is the sample code you can copy/paste into your theme function and continue from there.

<?php
add_filter( 'lps_filter_tile_patterns', 'my_theme_lps_filter_tile_patterns', 1 );
add_filter( 'lps_filter_display_posts_list', 'my_theme_lps_filter_display_posts_list', 1 );
add_filter( 'lps_filter_use_custom_tile_markup', 'my_theme_lps_filter_use_custom_tile_markup', 1, 2 );
add_filter( 'lps_filter_use_custom_section_markup_start', 'my_theme_lps_filter_use_custom_section_markup_start', 10, 3 );
add_filter( 'lps_filter_use_custom_section_markup_end', 'my_theme_lps_filter_use_custom_section_markup_end', 10, 3 );

if ( ! function_exists( 'my_theme_lps_filter_tile_patterns' ) ) {
	/**
	 * Add the theme custom tile patterns into the 3rd-party plugin.
	 * The rules for defining your custom tile pattern are:
	 * - the key must be numeric (put the keys >= 30, so that you will
	 *not override the plugin default patterns)
	 * - the value must be [_custom_HOW_YOU_CALL_THE_PATTERN]
	 * (please note the _custom_ string)
	 *
	 * @param  array $tile_pattern The list of defined tile patterns.
	 * @return array
	 */
	function my_theme_lps_filter_tile_patterns( $tile_pattern ) {
		/*
		Uncomment the line below if you want to restrict the patterns
		to only these you define here.
		*/
		// $tile_pattern = array();

		$tile_pattern[30] = '[_custom_my_tile_1]';
		$tile_pattern[31] = '[_custom_my_tile_2]';
		$tile_pattern[32] = '[_custom_my_tile_3]';

		return $tile_pattern;
	}
}

if ( ! function_exists( 'my_theme_lps_filter_display_posts_list' ) ) {
	/**
	 * Add the theme custom tile patterns descriptions into
	 * the 3rd-party plugin.
	 * The rules for defining your custom display list are:
	 * - the key must be one of the tile patterns you already
	 * defined (without the brackets)
	 * - the value must be a meaningful description of the output.
	 *
	 * @param  array $display_list  The list of defined tile patterns, with their descriptions.
	 * @return array
	 */
	function my_theme_lps_filter_display_posts_list( $display_list ) {
		/*
		Uncomment the line below if you want to restrict the list
		to only these you define here.
		*/
		// $display_list = array();

		$display_list['_custom_my_tile_1'] = __( 'My Theme Tile 1', 'text-domain' );
		$display_list['_custom_my_tile_2'] = __( 'My Theme Tile 2', 'text-domain' );
		$display_list['_custom_my_tile_3'] = __( 'My Theme Tile 3', 'text-domain' );

		return $display_list;
	}
}

if ( ! function_exists( 'my_theme_lps_filter_use_custom_tile_markup' ) ) {
	/**
	 * Create the custom output of tiles into the 3rd-party
	 * plugin (the markup and logic of the tiles).
	 * @param  string $tile_pattern The tile pattern slug.
	 * @param  object $post         The WP Post object to be rendered.
	 * @return string
	 */
	function my_theme_lps_filter_use_custom_tile_markup( $tile_pattern, $post ) {
		switch ( $tile_pattern ) {
			case '[_custom_my_tile_2]':
				setup_postdata( $post );
				ob_start();
				get_template_part( 'template-parts/content', 'custom-tile-2' );
				$tile_pattern = ob_get_clean();
				break;

			case '[_custom_my_tile_3]':
				setup_postdata( $post );
				ob_start();
				get_template_part( 'template-parts/content', 'custom-tile-3' );
				$tile_pattern = ob_get_clean();
				break;

			case '[_custom_my_tile_1]':
			default :
				setup_postdata( $post );
				ob_start();
				get_template_part( 'template-parts/content', 'custom-tile-1' );
				$tile_pattern = ob_get_clean();
				break;
		}

		return $tile_pattern;
	}
}

if ( ! function_exists( 'my_theme_lps_filter_use_custom_section_markup_start' ) ) {
	/**
	 * Alter the output of section start into the 3rd-party
	 * plugin (the markup before the tiles).
	 * @param  string $tile_pattern The tile pattern slug.
	 * @param  string $shortcode_id The section element id.
	 * @param  string $class        Custom class.
	 * @return string
	 */
	function my_theme_lps_filter_use_custom_section_markup_start( $tile_pattern, $shortcode_id = '', $class = '' ) {
		switch ( $tile_pattern ) {
			case '[_custom_my_tile_3]':
				$start = '';
				break;

			case '[_custom_my_tile_1]':
			case '[_custom_my_tile_2]':
			default :
				$start  = '<div id="' . esc_attr( $shortcode_id ) . '" class="related ' . esc_attr( $class ) . '">';
				$start .= esc_html__( 'Some cool articles', 'text-domain' );
				break;
			}
		return $start;
	}
}

if ( ! function_exists( 'my_theme_lps_filter_use_custom_section_markup_end' ) ) {
	/**
	 * Alter the output of section end into the 3rd-party plugin (the markup after the tiles).
	 * @param string $tile_pattern The tile pattern slug.
	 * @param string $shortcode_id The section element id.
	 * @param string $class Custom class.
	 * @return string
	 */
	function my_theme_lps_filter_use_custom_section_markup_end( $tile_pattern, $shortcode_id = '', $class = '' ) {
		switch ( $tile_pattern ) {
			case '[_custom_my_tile_3]':
				$end = '';
				break;
			case '[_custom_my_tile_1]':
			case '[_custom_my_tile_2]':
			default:
				$end = '</div>';
				break;
		}
		return $end;
	}
}
?>

Here is a sample of the template part (in my theme I have /template-parts/content-custom-tile-1.php)

<?php
/**
* Template part for displaying my custom tile.
*
* @package my_theme
*/

?>

<a href="<?php the_permalink(); ?>" class="my-custom-class">
	<div class="photo-wrapper">
		<?php the_thumbnail(); ?>
	</div>
	<div class="text">
		<h2><?php the_title(); ?></h2>
		<h5><?php the_author(); ?> – <?php the_date(); ?></h5>
	</div>
</a>

Get the example file with one custom template defined from here: