Buffy. Some sim instructors will shy away from anything that smacks of "non-standard".
Yet the simulator is a fantastic tool in the right hands. Real time, as you rightly say, is a time-waster (in my view, that is). I recall an excellent article in a flight safety magazine where a pilot wrote in and complained about the play-acting that was a required part of each sim session - particularly on LOFT exercises. He stated that he had never trained as an actor and found it difficult to make up his lines when talking on the sim intercom to ficticious ATC, cabin crew members and ground staff attached to the lead below. An interesting point.
If you would like to do a single pilot split-**** circuit or some other fun/serious but awfully non-standard (shudder) flying sequence that is not in the official syllabus, then simply ask your simulator instructor. Hopefully he will say go ahead.