remove all products in array from feed.

remove-products-from-queue.php

<php?

function remove_some_products_from_the_queue( $products, $feed_id ) {

   // Products to remove from the feed
   $products_to_remove = array(
      '20890',
      '20891',
      '20972',
   );

   return array_diff( $products, $products_to_remove );
}

add_filter( 'wppfm_products_in_feed_queue', 'remove_some_products_from_the_queue', 10, 2 );