Hello,
For logged-in users, you need to pass the user ID to this code
$post_ids = get_user_meta( $user_id, 'mbfp_posts', true );
to get the user meta. For example:
$post_ids = get_user_meta( 123, 'mbfp_posts', true ); //123 is the user ID
You can contact Bricks support and ask them how to get the user ID in the loop.
If you are not able to complete the task, we offer a customization service with an extra fee. Please contact us here for more details https://metabox.io/contact/