If you are looking to run shorter distances outdoors (100/200) then repeating the SPP 400m s-to-l may not do you any harm IMO (though some of the more experienced coaches/athletes may have something to say about that). I know Charlie has mentioned the use of shorter competition distances to supplement the season for a 400m runner on this sort of programme with competition period training distances of 120 and 150 (mentioned on this thread).