A RIMS (or HERMS) system isn't set up any differently than any other equipment profile. In version 2.3, the additional water needed for the heating circuit would be entered under "Mash Tun Addition," assuming it's recoverable wort. With the new version, only unrecoverable wort is entered as a mash tun loss.
Your mash temperature profile is the section that reflects your RIMS or a HERMS setup. The Rise Time of each mash step should reflect how long it takes your heating circuit to get you to the next plateau. The Step Time is, of course, how long you want to stay at that rest. Entered accurately, the timer will track with your equipment.