Disclaimer: I wasn't a SUPPO...
A friend of mine was a SUPPO and interviewed for a NSW billet. He flew himself up to Little Creek and met with some of the command. Expect to PT with them during their daily routine. I think he was there for most of the day. He thought it went well but didn't get picked up. I can't remember if it was a PERS/timing issue or if there was just a better candidate.
He had to do a boat tour as a DISBO first, so this NSW billet was a second tour option for him.