I was able to figure out how to do something similar, though not exactly what you need. I added the lines
<?php
$id = bbp_get_user_id();
header('Location: ../profile/?user='.$id);
?>
to the top of user-details.php. My project loads to a profile page with a GET request, but if you could find the function that returns the desired username you can redirect to any page you want. It’s a dirty fix but it works well for me.
