Listed can only be in afwatch, in a GUI that can listen a port. When you listen tasks, afrender sending child process(es) output directly into some socket. So, listening does not go though afserver, afrender -> afwatch direct connection needed. Browser (web gui) does not listen any port, afrender can't connect(send) anything to it directly.
Delete render from server store is accessible only in admin more. Afwatch: "Delete Client" menuitem. WebGUI: "DEL" button in "POW" buttons block.
ETA is the same in both GUIs. But some version can have ETA only in web gui. Almost all new GUI things appear in a web gui first (java-scripting is more easy than Qt programming). Then (after some tests and turning) GUI feature appears in afwatch. But some version can be created in hurry (due some heed feature or bug). So afwatch can miss something.