Khaled, I think he just meant a 60 second timeout timer on receiving an initial LIST reply numeric, as a test to make sure that the server actually got the LIST command. Just a short primer window.
If somebody is lagging so bad (>60 seconds) AND they keep sending new /list commands to the server every 60 seconds, then that's on them. The server doesn't care anymore if you hammer them with /list commands, they've got plenty of resources today.
