Pods_echo_tag.php

<?php
/*
   Set my_theme_t function as allowed for pods echo tag
*/
function my_theme_pods_template_echo_tag_allowed_functions($funcs) {
    return array_merge($funcs, array('my_theme_t'));
}
add_filter('pods_template_echo_tag_allowed_functions', 'my_theme_pods_template_echo_tag_allowed_functions');
/*
    Add "echo" tag to Pods Template
    signature: {@="TEXT",FILTER}
*/
function my_theme_pods_template_echo($code) {
  $allowed_functions = apply_filters('pods_template_echo_tag_allowed_functions', array() );
  $echo_tag_rx = '/{@="([^"]*)"\,?([^}]*)}/m';
  $matches = array();

  return preg_replace_callback($echo_tag_rx, function ($matches) use ($allowed_functions) {
    // return value "as is" if no valid filter passed
    $executed = $matches[1];

    if (in_array($matches[2], $allowed_functions)) {
        $executed = call_user_func($matches[2], $matches[1]);
    }

    return $executed;
  }, $code);
}
add_filter('pods_templates_pre_template', 'my_theme_pods_template_echo');