For sure.
Follow these steps:
1. In WP Show Posts create a new List, and name it related
1.1 Set the Post Type to Post and Posts per page to the number of posts you want to display eg. 4.
1.2 DO NOT set a taxonomy.
1.3 Set the Columns, Images, Content as you would do any other list.
1.4 Publish that.
2. Now create a new Hook Element in Appearance > Elements.
2.1 Add this PHP to the Element:
<div class="wpsp-related-posts grid-container">
<h2>Related Posts</h2>
<?php
if ( is_single() ) {
$cats = get_the_category();
$cat = $cats[0];
} else {
$cat = get_category( get_query_var( 'cat' ) );
}
$cat_slug = $cat->slug;
$list = get_page_by_title( 'related', 'OBJECT', 'wp_show_posts' );
wpsp_display( $list->ID, 'tax_term="' . $cat_slug . '"' );
?>
</div>
2.2 Set the Hook to where you want it displayed eg. generate_after_content
2.3 Check Execute PHP
2.4 Set the Display Rules to Posts > All Posts