We found an issue in production with config listeners piling up in the config_event gen_event server. This was due to how we fixed the API inconsistencies. We had re-parented the handler supervision to the config gen_server instead of the process that wanted config notifications. This means that since config never dies the handlers are never removed. The proposed patch just removes the config gen_server and uses a dedicated gen_server per event handler that handles the gen_event_EXIT messages. PR incoming after I have a ticket number.