Should the managed approach be used with large or small joint spacing?

The managed approach, which is based on the Carvalho or Gibsons methods, see page 10-10 and 10-11 in the Bench Design Tutorial, should be used with infinite persistence and small spacing.  Neither method utilizes persistence in any way and both methods look at the maximum size wedge.  If you do use persistence, then you should consider a larger design threshold for the analysis.