I entered a
suggestion in bugtracker. It suggests recording (and passing through) the id that ad_schedule_proc gets from ns_schedule_proc, rather than throwing it away. I will provide a patch that implements it shortly. However, I won't apply such a change before someone more experienced reviews and approves my contribution.
That said, Dennis Khitrov's suggestion of relying on AOLserver's functionality, specifically the undocumented [ns_info scheduled], has a lot of appeal. It would be simpler and more robust than then current solution. But it would be a bigger change.