add post thumbnail to rss, & add user avatar comment to rss

I made the plugin back in 2017 to make the rss feed look nicer feel free to use parts of the code in ASE to make the rss feed look better.

<?php
/*
Plugin Name: Pro Rss
Plugin URI: 
Description: This plugin adds post thumb search Tag & Related Post to RSS Feed 1&2 . 
Version: 1.2
Author: Press Themes & BAProdoction
Author URI: Press Themes & BAProdoction
License: GPL3
*/
?>
<?php
/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, orss code. A hook is a PHP function call that occurs sizeen a specific event occurs.

(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
?>

<?php 
//----------Extract Post Thumbnail For Manul Sizing----------//
function wpgym_extract_post_thumb( $str ){
    $matches = array();
    $pattern = '/src=[\'"]?([^\'" >]+)[\'" >]/';
    $match = preg_match( $pattern, $str, $matches );
    return($matches[1]);
}
//----------Display The Relted Posts----------//
function related_post() {
 
	global $wpdb, $post, $table_prefix;
 
	if ($post->ID) {
 
		$retval = '
<br clear="all"/><hr/>Related Post: ';
 
		// Get tags
		$tags = wp_get_post_tags($post->ID);
		$tagsarray = array();
		foreach ($tags as $tag) {
			$tagsarray[] = $tag->term_id;
		}
		$tagslist = implode(',', $tagsarray);
 
		// Do the query
		$q = "
			SELECT p.*, count(tr.object_id) as count
			FROM $wpdb->term_taxonomy AS tt, $wpdb->term_relationships AS tr, $wpdb->posts AS p
			WHERE tt.taxonomy ='post_tag'
				AND tt.term_taxonomy_id = tr.term_taxonomy_id
				AND tr.object_id  = p.ID
				AND tt.term_id IN ($tagslist)
				AND p.ID != $post->ID
				AND p.post_status = 'publish'
				AND p.post_date_gmt < NOW()
			GROUP BY tr.object_id
			ORDER BY count DESC, p.post_date_gmt DESC
			LIMIT 5;";
 
		$related = $wpdb->get_results($q);
 
		if ( $related ) {
			foreach($related as $r) {
				$retval .= '
	<span><a title="'.wptexturize($r->post_title).'" href="'.get_permalink($r->ID).'">'.wptexturize($r->post_title).'</a></span> | 
';
			}
		} else {
			$retval .= '
	<span>No related posts found</span>
';
		}
		$retval .= '<hr/>
';
		return $retval;
	}
	return;
}
//----------Display Mp3----------//
function PostAudio(){
if (function_exists("insert_audio_player")) {
	$audiofile = get_post_meta($post->ID, audio, true);
	$author = get_the_author();
	$podcasttitle = get_the_title($post->ID);
	// do we have one?
	if($audiofile) 	{
		return''.insert_audio_player('[audio:'.$audiofile.'|titles='.$podcasttitle.'|artists='.$author.'|width=100%]').' 
		<a href="' . get_bloginfo ( 'url' ).'/audio/'.$audiofile.'">Click to Download the Audio File</a>' . get_bloginfo ( 'audio' ).'';
	}
}
}
//----------Display The Modify Rss Feed----------//
function postTitle($title) {
return $title;
}
function PostThumb($content) {
if($content){ $content = $content; $brake = '';  }else{ $content = '<br/>'; $brake = '<br/>';}//Check if the post has content .
	if(current_theme_supports('post-thumbnails')){//Check if the theme has Post Thumbnail Support.
		if(has_post_thumbnail()) { //Check if the post has a Post Thumbnail assigned to it.
			$body ='<img width="100" height="100" alt="Post Thumnale" src="'.wpgym_extract_post_thumb(get_the_post_thumbnail()).'" class="wp-post-image alignleft" align="left"><div align="justify">'.$content.'</div>'.$brake.''.related_post().''.PostAudio().'Tags: '.get_the_tag_list('',', ','<br/>').'<hr/>';
		}else{
			$body ='<img width="100" height="100" alt="Placer Hoilder IMG" src="'.plugins_url('images/place-Holder.png' , __FILE__).'" class="wp-post-image alignleft" align="left"><div align="justify">'.$content.'</div>'.$brake.''.related_post().''.PostAudio().'Tags: '.get_the_tag_list('',', ','<br/>').'<hr/>';
		}
	}else{
	$body ='<div align="justify">'.$content.'</div>'.$brake.''.related_post().''.PostAudio().'Tags: '.get_the_tag_list('',', ','<br/>').'<hr/>';
	}
    return $body;
}
add_filter('the_title_rss', 'postTitle');
add_filter('the_excerpt_rss', 'PostThumb');
add_filter('the_content_rss', 'PostThumb');
//----------Display The Modify Rss Feed----------//
function excerpt_ellipse($text) {
   return'<script>
function removeElement(id) {
  var element = document.getElementById(id);
  element.parentNode.removeChild(element);
}
window.onload = function() {  
  removeElement("more")  
};  
</script>'.$text.''; 
}
add_action('do_feed', 'excerpt_ellipse', 1);
add_action('do_feed_rdf', 'excerpt_ellipse', 1);
add_action('do_feed_rss', 'excerpt_ellipse', 1);
add_action('do_feed_rss2', 'excerpt_ellipse', 1);
add_action('do_feed_atom', 'excerpt_ellipse', 1);
add_filter('the_excerpt_rss', 'excerpt_ellipse',1);
add_filter('the_content_rss', 'excerpt_ellipse',1);
?>

@pressthemes1 thank you for the suggestion and code. This is well noted for now.