#2, but for clarity: A) hh:mm:ss is based on CP time, or the virtual TOD in the virtual machine? B) what happens in a SSI configuration if a virtual machine moves to a new CP with a different clock?
If only #2 were implemented, the new SPOOL command could be entered in the directory entry of such servers via the 'COMMAND' statement, providing the same facility with lower CP coding and documentation requirements. New products could be distributed with sample directory entries containing the "AT hh:mm:ss" included, perhaps as a comment.