So I figured it out. In output-generator.php I modified three lines of code on lines 271, 274 and 293.
$output .= '<a href="' . get_permalink( $result->ID ) . '" ' . $link_attributes . ' class="crp_title">' . $title . '</a>';
I changed to:
$output .= '<a href="' . get_permalink( $result->ID ) . '<strong>?utm_source=mysite&utm_medium=relatedposts&utm_campaign=internal</strong>" ' . $link_attributes . ' class="crp_title">' . $title . '</a>';
And everything seems to be working correctly.
Just wanted to put this out there for anyone who wants to do the same, and I think this would be a valuable option to add in the setting since I am sure this will not survive an update.