I have been in the URNU, and would like to join the RNR. Before approaching my CO, I was just wondering what people's experiences were - did being in the URNU smooth the process? Was the URNU involved at all, even? What were the steps of the process?
The only thing that transfers across is the service number.
Undergrads joining an URNU don't usually sit a recruiting test or undergo an official service interview, a full service medical, complete a PJFT, gain SC or undergo AIB. All of this needs completing to join the RNR as an officer.
Generally it's a good idea to ask your CO if he/she is happy to be a nominated referee.