Lars, you rock. This is exactly what I needed for a "Client" related list that I have for Change Orders. We have a M2M relationship with clients (it's a user table) and change requests. All I had to add was:

uri.set('sysparm_query','u_active=true');

to the script for the "Edit..." button (and of course set the table on the button), and it works like a dream. Thank you!