[Support request] Setting a custom image size for the featured post

Let’s try this:

add_filter( 'wpsp_default_image_size', function( $size, $settings ) {
    if ( 123 === (int) $settings['list_id'] && $settings['featured_post'] ) {
        return 'full';
    }

    return $size;
}, 10, 2 );

add_filter( 'wpsp_settings', function( $settings ) {
    $settings['featured_post'] = wpsp_get_setting( $settings[ 'list_id' ], 'wpsp_featured_post' );
	
    return $settings;
} );