Update:
More research lead me to the following snippet I made which works but the “original” featured image which is shown by WPSP is still there as well.
add_action( 'wpsp_inside_image_container', function( $settings ) {
if ( 10449 === $settings['list_id'] ) {
$image = get_post_meta( get_the_ID(), '2nd_featured_image', true );
if( get_field('2nd_featured_image') ):
?><a href="<?php the_permalink(); ?>"><img src="<?php the_field('2nd_featured_image'); ?>" alt="" /></a><?php
endif;
}
} );
Is there a way to disable the WPSP image?