Remove tag on my RSS Feed

I believe the most direct way of customizing WordPress feeds is to hook into them directly with the following filter.
Edit: as we talked about, let’s just edit the content to tear out any

function edit_your_feed_content($content) {
    $content = preg_replace("/(<figure.*?[^>]*>)(.*?)(<\/figure>)/i", "", $content);
    return $content;
}
add_filter('the_content', 'edit_your_feed_content');