Issabel has a failry complete ACL system (System - Users - Group Permissions) that lets you restrict features to a specific group, I have just tried by modifying the Operator group ( Show Filter - Operator) and leaving only enabled PBXConfig - Monitoring and went thorugh other menus and disabled them. Once logged as a user in the Operator Group, Issabel GUI only shows the menu PBX - Call Recordigs.
No configuration text file was modified at all, all through GUI. So I can say that Web UI does have that feature and many others, I recommend you to inspect menus one by one and read a bit on their names and figure out what they might do, before making an incorrect affirmation about product features.. in any case you can say that "I cannot find the option in web UI", instead of saying that it does not have the feature.
Other users might come by, and beleive your incorrect claim, so I am forced to write this reply, it is nothing personal. Go play with groups and group permissions, and other issabel menus... you might be surprised as you might be able to do many things you though were not possible.