Actually found a solution and was so much easier than expected, if anyone else needs this…
add_filter('acf/fields/post_object/result', 'my_post_object_result', 10, 4);
function my_post_object_result( $text, $post, $field, $post_id ) {
/* Get whatever value you want here e.g. */
$text .= ' (' . tribe_get_venue($post->ID) . ')';
/* do any other processing you might want to do before returning it... */
return $text;
}