Settings->Rollouts->General Settings tick the boxes for 'Cube decisions use same settings same as checker play' and 'Use same settings for both players'
Settings->Rollouts->First Play Both - select Expert here (this is my opinion). When doing rollouts, most of the time Expert play will be more than strong enough if you do say 1296 trials with no truncation. The rollout function has an enormous number of options, most of which are only useful when trying to investigate special positions. The simple expert setting for both players is probably more accurate than any of the Analysis functions. The downside is that rolling out 1296 trials of an early move in a game can take a couple of hours. On World Class or Supremo rollout settings, it can take more than 24 hours of computing time.